Allow TLSv1 for compatibility with older devices

(cherry picked from commit 14156235863358631c3ff0d2917513b9c9280eba)

.envrc

@@ -0,0 +1,3 @@
+# shellcheck shell=bash
+
+use flake

.gitignore

@@ -1 +1,3 @@
 result
+.direnv
+.pre-commit-config.yaml

.gitlab-ci.yml

@@ -1,13 +1,18 @@
+.hydra-cli:
+  image: docker.nix-community.org/nixpkgs/nix-flakes
+  script:
+    - nix run --inputs-from ./. nixpkgs#hydra-cli -- -H https://hydra.nix-community.org jobset-wait simple-nixos-mailserver "${jobset}"
+
 hydra-pr:
+  extends: .hydra-cli
   only:
     - merge_requests
-  image: nixos/nix
+  variables:
-  script:
+    jobset: $CI_MERGE_REQUEST_IID
-    - nix-shell -I nixpkgs=channel:nixos-22.05 -p hydra-cli --run 'hydra-cli -H https://hydra.nix-community.org jobset-wait simple-nixos-mailserver ${CI_MERGE_REQUEST_IID}'
 
 hydra-master:
+  extends: .hydra-cli
   only:
     - master
-  image: nixos/nix
+  variables:
-  script:
+    jobset: master
-    - nix-shell -I nixpkgs=channel:nixos-22.05 -p hydra-cli --run 'hydra-cli -H https://hydra.nix-community.org jobset-wait simple-nixos-mailserver master'

.hydra/declarative-jobsets.nix

@@ -4,22 +4,21 @@ let
   pkgs = import nixpkgs { };
 
   prs = builtins.fromJSON (builtins.readFile pulls);
-  prJobsets =  pkgs.lib.mapAttrs (num: info:
+  prJobsets = pkgs.lib.mapAttrs (num: info: {
-    { enabled = 1;
+    enabled = 1;
     hidden = false;
     description = "PR ${num}: ${info.title}";
-      checkinterval = 30;
+    checkinterval = 300;
     schedulingshares = 20;
     enableemail = false;
     emailoverride = "";
     keepnr = 1;
     type = 1;
     flake = "gitlab:simple-nixos-mailserver/nixos-mailserver/merge-requests/${info.iid}/head";
-    }
+  }) prs;
-  ) prs;
   mkFlakeJobset = branch: {
     description = "Build ${branch} branch of Simple NixOS MailServer";
-    checkinterval = "60";
+    checkinterval = 300;
     enabled = "1";
     schedulingshares = 100;
     enableemail = false;
@@ -32,8 +31,8 @@ let
 
   desc = prJobsets // {
     "master" = mkFlakeJobset "master";
-    "nixos-22.11" = mkFlakeJobset "nixos-22.11";
+    "nixos-25.05" = mkFlakeJobset "nixos-25.05";
-    "nixos-23.05" = mkFlakeJobset "nixos-23.05";
+    "nixos-25.11" = mkFlakeJobset "nixos-25.11";
   };
 
   log = {
@@ -41,13 +40,14 @@ let
     jobsets = desc;
   };
 
-in {
+in
+{
   jobsets = pkgs.runCommand "spec-jobsets.json" { } ''
-    cat >$out <<EOF
+    cat >$out <<'EOF'
     ${builtins.toJSON desc}
     EOF
     # This is to get nice .jobsets build logs on Hydra
-    cat >tmp <<EOF
+    cat >tmp <<'EOF'
     ${builtins.toJSON log}
     EOF
     ${pkgs.jq}/bin/jq . tmp

.readthedocs.yaml

@@ -5,17 +5,18 @@
 version: 2
 
 build:
-  os: ubuntu-22.04
+  os: ubuntu-24.04
   tools:
     python: "3"
   apt_packages:
-    - nix
+    - curl
     - proot
   jobs:
     pre_install:
-      - mkdir -p ~/.nix ~/.config/nix
+      - curl -L https://github.com/DavHau/nix-portable/releases/latest/download/nix-portable-$(uname -m) > ./nix-portable
-      - echo "experimental-features = nix-command flakes" > ~/.config/nix/nix.conf
+      - chmod +x ./nix-portable
-      - proot -b ~/.nix:/nix /bin/sh -c "nix build -L .#optionsDoc && cp -v result docs/options.md"
+      - ./nix-portable nix build --print-build-logs .#optionsDoc
+      - ./nix-portable nix store cat $(readlink result) > docs/options.md
 
 sphinx:
    configuration: docs/conf.py

README.md

@@ -1,75 +1,85 @@
 # ![Simple Nixos MailServer][logo]
+
 ![license](https://img.shields.io/badge/license-GPL3-brightgreen.svg)
 [![pipeline status](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/badges/master/pipeline.svg)](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/commits/master)
 
-
 ## Release branches
 
 For each NixOS release, we publish a branch. You then have to use the
 SNM branch corresponding to your NixOS version.
 
-* For NixOS 23.05
+* For NixOS 25.11
-   - Use the [SNM branch `nixos-23.05`](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/tree/nixos-23.05)
+  * Use the [SNM branch `nixos-25.11`](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/tree/nixos-25.11)
-   - [Documentation](https://nixos-mailserver.readthedocs.io/en/nixos-23.05/)
+  * [Documentation](https://nixos-mailserver.readthedocs.io/en/nixos-25.11/)
-   - [Release notes](https://nixos-mailserver.readthedocs.io/en/nixos-23.05/release-notes.html#nixos-23-05)
+  * [Release notes](https://nixos-mailserver.readthedocs.io/en/nixos-25.11/release-notes.html#nixos-25-11)
-* For NixOS 22.11
+* For NixOS 25.05
-   - Use the [SNM branch `nixos-22.11`](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/tree/nixos-22.11)
+  * Use the [SNM branch `nixos-25.05`](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/tree/nixos-25.05)
-   - [Documentation](https://nixos-mailserver.readthedocs.io/en/nixos-22.11/)
+  * [Documentation](https://nixos-mailserver.readthedocs.io/en/nixos-25.05/)
-   - [Release notes](https://nixos-mailserver.readthedocs.io/en/nixos-22.11/release-notes.html#nixos-22-11)
+  * [Release notes](https://nixos-mailserver.readthedocs.io/en/nixos-25.05/release-notes.html#nixos-25-05)
 * For NixOS unstable
-   - Use the [SNM branch `master`](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/tree/master)
+  * Use the [SNM branch `master`](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/tree/master)
-   - [Documentation](https://nixos-mailserver.readthedocs.io/en/latest/)
+  * [Documentation](https://nixos-mailserver.readthedocs.io/en/latest/)
-
-[Subscribe to SNM Announcement List](https://www.freelists.org/list/snm)
-This is a very low volume list where new releases of SNM are announced, so you
-can stay up to date with bug fixes and updates.
-
 
 ## Features
-### v2.0
+
 * [x] Continous Integration Testing
 * [x] Multiple Domains
- * Postfix MTA
+* Postfix
-    - [x] smtp on port 25
+  * [x] SMTP on port 25
-    - [x] submission tls on port 465
+  * [x] Submission TLS on port 465
-    - [x] submission starttls on port 587
+  * [x] Submission StartTLS on port 587
-    - [x] lmtp with dovecot
+  * [x] LMTP with Dovecot
+  * [x] DANE and MTA-STS validation
+  * [x] SMTP TLS Reports ([RFC 8460](https://www.rfc-editor.org/rfc/rfc8460))
 * Dovecot
-    - [x] maildir folders
+  * [x] Maildir folders
-    - [x] imap with tls on port 993
+  * [x] IMAP with TLS on port 993
-    - [x] pop3 with tls on port 995
+  * [x] POP3 with TLS on port 995
-    - [x] imap with starttls on port 143
+  * [x] IMAP with StartTLS on port 143
-    - [x] pop3 with starttls on port 110
+  * [x] POP3 with StartTLS on port 110
 * Certificates
-    - [x] manual certificates
+  * [x] ACME
-    - [x] on the fly creation
+  * [x] Custom certificates
-    - [x] Let's Encrypt
 * Spam Filtering
-    - [x] via rspamd
+  * [x] Via Rspamd
 * Virus Scanning
-    - [x] via clamav
+  * [x] Via ClamAV
 * DKIM Signing
-    - [x] via opendkim
+  * [x] Via Rspamd
 * User Management
-    - [x] declarative user management
+  * [x] Declarative user management
-    - [x] declarative password management
+  * [x] Declarative password management
- * Sieves
+  * [x] LDAP users
-    - [x] A simple standard script that moves spam
+* Sieve
-    - [x] Allow user defined sieve scripts
+  * [x] Allow user defined sieve scripts
-    - [x] ManageSieve support
+  * [x] Moving mails from/to junk trains the Bayes filter
+  * [x] ManageSieve support
 * User Aliases
-    - [x] Regular aliases
+  * [x] Regular aliases
-    - [x] Catch all aliases
+  * [x] Catch all aliases
+* Improve the Forwarding Experience
+  * [x] [Sender Rewriting Scheme](https://en.wikipedia.org/wiki/Sender_Rewriting_Scheme)
 
 ### In the future
 
+* Automatic client configuration
+  * [ ] [Autoconfig](https://web.archive.org/web/20210624004729/https://developer.mozilla.org/en-US/docs/Mozilla/Thunderbird/Autoconfiguration)
+  * [ ] [Autodiscovery](https://learn.microsoft.com/en-us/exchange/architecture/client-access/autodiscover?view=exchserver-2019)
+  * [ ] [Mobileconfig](https://support.apple.com/guide/profile-manager/distribute-profiles-manually-pmdbd71ebc9/mac)
 * DKIM Signing
-    - [ ] Allow a per domain selector
+  * [ ] Allow per domain selectors
+  * [ ] Allow passing DKIM signing keys
+* Improve the Forwarding Experience
+  * [ ] Support [ARC](https://en.wikipedia.org/wiki/Authenticated_Received_Chain) signing with [Rspamd](https://rspamd.com/doc/modules/arc.html)
+* User management
+  * [ ] Allow local and LDAP user to coexist
+* OpenID Connect
+  * Depends on relevant clients adding support, e.g. [Thunderbird](https://bugzilla.mozilla.org/show_bug.cgi?id=1602166)
 
 ### Get in touch
 
-- Subscribe to the [mailing list](https://www.freelists.org/archive/snm/)
+* Matrix: [#nixos-mailserver:nixos.org](https://matrix.to/#/#nixos-mailserver:nixos.org)
-- Join the Libera Chat IRC channel `#nixos-mailserver`
+* IRC: `#nixos-mailserver` on [Libera Chat](https://libera.chat/guides/connect)
 
 ## How to Set Up a 10/10 Mail Server Guide
 
@@ -82,16 +92,18 @@ For a complete list of options, [see in readthedocs](https://nixos-mailserver.re
 See the [How to Develop SNM](https://nixos-mailserver.readthedocs.io/en/latest/howto-develop.html) documentation page.
 
 ## Contributors
+
 See the [contributor tab](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/graphs/master)
 
 ### Alternative Implementations
+
 * [NixCloud Webservices](https://github.com/nixcloud/nixcloud-webservices)
 
 ### Credits
+
 * send mail graphic by [tnp_dreamingmao](https://thenounproject.com/dreamingmao)
    from [TheNounProject](https://thenounproject.com/) is licensed under
    [CC BY 3.0](http://creativecommons.org/~/3.0/)
 * Logo made with [Logomakr.com](https://logomakr.com)
 
-
 [logo]: docs/logo.png

default.nix

@@ -14,17 +14,64 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, lib, pkgs, ... }:
+{
-
+  config,
-with lib;
+  lib,
+  pkgs,
+  ...
+}:
 
 let
+  inherit (lib)
+    literalExpression
+    literalMD
+    mkDefault
+    mkEnableOption
+    mkOption
+    mkOptionType
+    mkRemovedOptionModule
+    mkRenamedOptionModule
+    types
+    warn
+    ;
+
   cfg = config.mailserver;
 in
 {
   options.mailserver = {
     enable = mkEnableOption "nixos-mailserver";
 
+    enableNixpkgsReleaseCheck = mkOption {
+      type = types.bool;
+      default = true;
+      description = ''
+        Whether to check for a release mismatch between NixOS mailserver and
+        Nixpkgs.
+
+        Using mismatched versions is likely to cause compatibility issues
+        and may require migrations that make an eventual rollback tricky.
+
+        It is therefore highly recommended to use a release of NixOS mailserver
+        that corresponds with your chosen release of Nixpkgs.
+      '';
+    };
+
+    stateVersion = mkOption {
+      type = types.nullOr types.ints.positive;
+      default = null;
+      description = ''
+        Tracking stateful version changes as an incrementing number.
+
+        When a new release comes out we may require manual migration steps to
+        be completed, before the new version can be put into production.
+
+        If your `stateVersion` is too low one or multiple assertions may
+        trigger to give you instructions on what migrations steps are required
+        to continue. Increase the `stateVersion` as instructed by the assertion
+        message.
+      '';
+    };
+
     openFirewall = mkOption {
       type = types.bool;
       default = true;
@@ -37,6 +84,46 @@ in
       description = "The fully qualified domain name of the mail server.";
     };
 
+    systemName = mkOption {
+      type = types.str;
+      default = "${cfg.systemDomain} mail system";
+      defaultText = literalExpression "\${config.mailserver.systemDomain} mail system";
+      example = "ACME Corp.";
+      description = ''
+        The sender name given in automated reports.
+      '';
+    };
+
+    systemContact = mkOption {
+      type = types.str;
+      example = "postmaster@example.com";
+      description = ''
+        The email address where the administrative contact for this mail server is reachable.
+
+        Currently, this is only required when one of the following features is enabled:
+        - SMTP TLS reports (`mailserver.tlsrpt.enable`)
+      '';
+    };
+
+    systemDomain = mkOption {
+      type = types.str;
+      default =
+        if (config.networking.domain != null && lib.elem config.networking.domain cfg.domains) then
+          config.networking.domain
+        else
+          lib.head cfg.domains;
+      defaultText = literalExpression ''
+        if config.networking.domain != null && lib.elem config.networking.domain cfg.domains then
+          config.networking.domain
+        else
+          lib.head cfg.domains
+      '';
+      example = literalExpression "config.networking.domain";
+      description = ''
+        The primary domain used for sending automated reports.
+      '';
+    };
+
     domains = mkOption {
       type = types.listOf types.str;
       example = [ "example.com" ];
@@ -46,7 +133,10 @@ in
 
     certificateDomains = mkOption {
       type = types.listOf types.str;
-      example = [ "imap.example.com" "pop3.example.com" ];
+      example = [
+        "imap.example.com"
+        "pop3.example.com"
+      ];
       default = [ ];
       description = ''
         ({option}`mailserver.certificateScheme` == `acme-nginx`)
@@ -63,7 +153,10 @@ in
     };
 
     loginAccounts = mkOption {
-      type = types.attrsOf (types.submodule ({ name, ... }: {
+      type = types.attrsOf (
+        types.submodule (
+          { name, ... }:
+          {
             options = {
               name = mkOption {
                 type = types.str;
@@ -102,7 +195,10 @@ in
 
               aliases = mkOption {
                 type = with types; listOf types.str;
-            example = ["abuse@example.com" "postmaster@example.com"];
+                example = [
+                  "abuse@example.com"
+                  "postmaster@example.com"
+                ];
                 default = [ ];
                 description = ''
                   A list of aliases of this login account.
@@ -122,7 +218,10 @@ in
 
               catchAll = mkOption {
                 type = with types; listOf (enum cfg.domains);
-            example = ["example.com" "example2.com"];
+                example = [
+                  "example.com"
+                  "example2.com"
+                ];
                 default = [ ];
                 description = ''
                   For which domains should this account act as a catch all?
@@ -186,7 +285,9 @@ in
             };
 
             config.name = mkDefault name;
-      }));
+          }
+        )
+      );
       example = {
         user1 = {
           hashedPassword = "$6$evQJs5CFQyPAW09S$Cn99Y8.QjZ2IBnSu4qf1vBxDRWkaIZWOtmu1Ddsm3.H3CFpeVc0JU4llIq8HQXgeatvYhh5O33eWG3TSpjzu6/";
@@ -234,7 +335,7 @@ in
       tlsCAFile = mkOption {
         type = types.path;
         default = "${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt";
-        defaultText = lib.literalMD "see [source](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/blob/master/default.nix)";
+        defaultText = literalMD "see [source](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/blob/master/default.nix)";
         description = ''
           Certifificate trust anchors used to verify the LDAP server certificate.
         '';
@@ -268,7 +369,11 @@ in
       };
 
       searchScope = mkOption {
-        type = types.enum [ "sub" "base" "one" ];
+        type = types.enum [
+          "sub"
+          "base"
+          "one"
+        ];
         default = "sub";
         description = ''
           Search scope below which users accounts are looked for.
@@ -277,26 +382,26 @@ in
 
       dovecot = {
         userAttrs = mkOption {
-          type = types.str;
+          type = types.nullOr types.str;
-          default = "";
+          default = null;
           description = ''
             LDAP attributes to be retrieved during userdb lookups.
 
             See the users_attrs reference at
-            https://doc.dovecot.org/configuration_manual/authentication/ldap_settings_auth/#user-attrs
+            https://doc.dovecot.org/2.3/configuration_manual/authentication/ldap_settings_auth/#user-attrs
             in the Dovecot manual.
           '';
         };
 
         userFilter = mkOption {
           type = types.str;
-          default = "mail=%u";
+          default = "mail=%{user}";
-          example = "(&(objectClass=inetOrgPerson)(mail=%u))";
+          example = "(&(objectClass=inetOrgPerson)(mail=%{user}))";
           description = ''
             Filter for user lookups in Dovecot.
 
             See the user_filter reference at
-            https://doc.dovecot.org/configuration_manual/authentication/ldap_settings_auth/#user-filter
+            https://doc.dovecot.org/2.3/configuration_manual/authentication/ldap_settings_auth/#user-filter
             in the Dovecot manual.
           '';
         };
@@ -308,20 +413,20 @@ in
             LDAP attributes to be retrieved during passdb lookups.
 
             See the pass_attrs reference at
-            https://doc.dovecot.org/configuration_manual/authentication/ldap_settings_auth/#pass-attrs
+            https://doc.dovecot.org/2.3/configuration_manual/authentication/ldap_settings_auth/#pass-attrs
             in the Dovecot manual.
           '';
         };
 
         passFilter = mkOption {
           type = types.nullOr types.str;
-          default = "mail=%u";
+          default = "mail=%{user}";
-          example = "(&(objectClass=inetOrgPerson)(mail=%u))";
+          example = "(&(objectClass=inetOrgPerson)(mail=%{user}))";
           description = ''
             Filter for password lookups in Dovecot.
 
             See the pass_filter reference for
-            https://doc.dovecot.org/configuration_manual/authentication/ldap_settings_auth/#pass-filter
+            https://doc.dovecot.org/2.3/configuration_manual/authentication/ldap_settings_auth/#pass-filter
             in the Dovecot manual.
           '';
         };
@@ -373,14 +478,28 @@ in
         to resynchronize).
 
         Note the some variables can be used in the file path. See
-        https://doc.dovecot.org/configuration_manual/mail_location/#variables
+        https://doc.dovecot.org/2.3/configuration_manual/mail_location/#variables
         for details.
       '';
       example = "/var/lib/dovecot/indices";
     };
 
     fullTextSearch = {
-      enable = mkEnableOption "Full text search indexing with xapian. This has significant performance and disk space cost.";
+      enable = mkEnableOption ''
+        Full text search indexing with Xapian through the fts_flatcurve plugin.
+        This has significant performance and disk space cost.
+      '';
+      memoryLimit = mkOption {
+        type = types.nullOr types.int;
+        default = null;
+        example = 2000;
+        description = ''
+          Memory limit for the indexer process, in MiB.
+          If null, leaves the default (which is rather low),
+          and if 0, no limit.
+        '';
+      };
+
       autoIndex = mkOption {
         type = types.bool;
         default = true;
@@ -389,20 +508,22 @@ in
       autoIndexExclude = mkOption {
         type = types.listOf types.str;
         default = [ ];
-        example = [ "\\Trash" "SomeFolder" "Other/*" ];
+        example = [
+          "\\Trash"
+          "SomeFolder"
+          "Other/*"
+        ];
         description = ''
           Mailboxes to exclude from automatic indexing.
         '';
       };
 
-      indexAttachments = mkOption {
-        type = types.bool;
-        default = false;
-        description = "Also index text-only attachements. Binary attachements are never indexed.";
-      };
-
       enforced = mkOption {
-        type = types.enum [ "yes" "no" "body" ];
+        type = types.enum [
+          "yes"
+          "no"
+          "body"
+        ];
         default = "no";
         description = ''
           Fail searches when no index is available. If set to
@@ -412,46 +533,65 @@ in
         '';
       };
 
-      minSize = mkOption {
+      languages = mkOption {
-        type = types.int;
+        type = types.nonEmptyListOf types.str;
-        default = 2;
+        default = [ "en" ];
-        description = "Size of the smallest n-gram to index.";
+        example = [
-      };
+          "en"
-      maxSize = mkOption {
+          "de"
-        type = types.int;
+        ];
-        default = 20;
+        description = ''
-        description = "Size of the largest n-gram to index.";
+          A list of languages that the full text search should detect.
-      };
+          At least one language must be specified.
-      memoryLimit = mkOption {
+          The language listed first is the default and is used when language recognition fails.
-        type = types.nullOr types.int;
+          See <https://doc.dovecot.org/main/core/plugins/fts.html#fts_languages>.
-        default = null;
+        '';
-        example = 2000;
-        description = "Memory limit for the indexer process, in MiB. If null, leaves the default (which is rather low), and if 0, no limit.";
       };
 
-      maintenance = {
+      substringSearch = mkOption {
-        enable = mkOption {
         type = types.bool;
-          default = true;
+        default = false;
-          description = "Regularly optmize indices, as recommended by upstream.";
+        description = ''
+          If enabled, allows substring searches.
+          See <https://doc.dovecot.org/main/core/plugins/fts_flatcurve.html#fts_flatcurve_substring_search>.
+
+          Enabling this requires significant additional storage space.
+        '';
       };
 
-        onCalendar = mkOption {
+      headerExcludes = mkOption {
-          type = types.str;
+        type = types.listOf types.str;
-          default = "daily";
+        default = [
-          description = "When to run the maintenance job. See systemd.time(7) for more information about the format.";
+          "Received"
+          "DKIM-*"
+          "X-*"
+          "Comments"
+        ];
+        description = ''
+          The list of headers to exclude.
+          See <https://doc.dovecot.org/main/core/plugins/fts.html#fts_header_excludes>.
+        '';
       };
 
-        randomizedDelaySec = mkOption {
+      filters = mkOption {
-          type = types.int;
+        type = types.listOf types.str;
-          default = 1000;
+        default = [
-          description = "Run the maintenance job not exactly at the time specified with `onCalendar`, but plus or minus this many seconds.";
+          "normalizer-icu"
-        };
+          "snowball"
+          "stopwords"
+        ];
+        description = ''
+          The list of filters to apply.
+          <https://doc.dovecot.org/main/core/plugins/fts.html#filter-configuration>.
+        '';
       };
     };
 
     lmtpSaveToDetailMailbox = mkOption {
-      type = types.enum ["yes" "no"];
+      type = types.enum [
+        "yes"
+        "no"
+      ];
       default = "yes";
       description = ''
         If an email address is delimited by a "+", should it be filed into a
@@ -460,18 +600,40 @@ in
       '';
     };
 
+    lmtpMemoryLimit = mkOption {
+      type = types.int;
+      default = 256;
+      description = ''
+        The memory limit for the LMTP service, in megabytes.
+      '';
+    };
+
+    quotaStatusMemoryLimit = mkOption {
+      type = types.int;
+      default = 256;
+      description = ''
+        The memory limit for the quota-status service, in megabytes.
+      '';
+    };
+
     extraVirtualAliases = mkOption {
-      type = let
+      type =
+        let
           loginAccount = mkOptionType {
             name = "Login Account";
-          check = (account: builtins.elem account (builtins.attrNames cfg.loginAccounts));
+            check = account: builtins.elem account (builtins.attrNames cfg.loginAccounts);
           };
-      in with types; attrsOf (either loginAccount (nonEmptyListOf loginAccount));
+        in
+        with types;
+        attrsOf (either loginAccount (nonEmptyListOf loginAccount));
       example = {
         "info@example.com" = "user1@example.com";
         "postmaster@example.com" = "user1@example.com";
         "abuse@example.com" = "user1@example.com";
-        "multi@example.com" = [ "user1@example.com" "user2@example.com" ];
+        "multi@example.com" = [
+          "user1@example.com"
+          "user2@example.com"
+        ];
       };
       description = ''
         Virtual Aliases. A virtual alias `"info@example.com" = "user1@example.com"` means that
@@ -506,7 +668,10 @@ in
 
     rejectSender = mkOption {
       type = types.listOf types.str;
-      example = [ "@example.com" "spammer@example.net" ];
+      example = [
+        "example.com"
+        "spammer@example.net"
+      ];
       description = ''
         Reject emails from these addresses from unauthorized senders.
         Use if a spammer is using the same domain or the same sender over and over.
@@ -516,7 +681,10 @@ in
 
     rejectRecipients = mkOption {
       type = types.listOf types.str;
-      example = [ "sales@example.com" "info@example.com" ];
+      example = [
+        "sales@example.com"
+        "info@example.com"
+      ];
       description = ''
         Reject emails addressed to these local addresses from unauthorized senders.
         Use if a spammer has found email addresses in a catchall domain but you do
@@ -570,7 +738,7 @@ in
         - /var/vmail/example.com/user/.folder.subfolder/ (default layout)
         - /var/vmail/example.com/user/folder/subfolder/  (FS layout)
 
-        See https://wiki2.dovecot.org/MailboxFormat/Maildir for details.
+        See https://doc.dovecot.org/main/core/config/mailbox_formats/maildir.html#maildir-mailbox-format for details.
       '';
     };
 
@@ -591,7 +759,7 @@ in
         This affects how mailboxes appear to mail clients and sieve scripts.
         For instance when using "." then in a sieve script "example.com" would refer to the mailbox "com" in the parent mailbox "example".
         This does not determine the way your mails are stored on disk.
-        See https://wiki.dovecot.org/Namespaces for details.
+        See https://doc.dovecot.org/main/core/config/namespaces.html#namespaces for details.
       '';
     };
 
@@ -620,12 +788,30 @@ in
       };
     };
 
-    certificateScheme = let
+    certificateScheme =
-      schemes = [ "manual" "selfsigned" "acme-nginx" "acme" ];
+      let
-      translate = i: warn "Setting mailserver.certificateScheme by number is deprecated, please use names instead: 'mailserver.certificateScheme = ${builtins.toString i}' can be replaced by 'mailserver.certificateScheme = \"${(builtins.elemAt schemes (i - 1))}\"'."
+        schemes = [
+          "manual"
+          "selfsigned"
+          "acme-nginx"
+          "acme"
+        ];
+        translate =
+          i:
+          warn
+            "Setting mailserver.certificateScheme by number is deprecated, please use names instead: 'mailserver.certificateScheme = ${builtins.toString i}' can be replaced by 'mailserver.certificateScheme = \"${
+              (builtins.elemAt schemes (i - 1))
+            }\"'."
             (builtins.elemAt schemes (i - 1));
-    in mkOption {
+      in
-      type = with types; coercedTo (enum [ 1 2 3 ]) translate (enum schemes);
+      mkOption {
+        type =
+          with types;
+          coercedTo (enum [
+            1
+            2
+            3
+          ]) translate (enum schemes);
         default = "selfsigned";
         description = ''
           The scheme to use for managing TLS certificates:
@@ -675,11 +861,35 @@ in
       '';
     };
 
+    acmeCertificateName = mkOption {
+      type = types.str;
+      default = cfg.fqdn;
+      defaultText = literalExpression "config.mailserver.fqdn";
+      example = "example.com";
+      description = ''
+          ({option}`mailserver.certificateScheme` == `acme`)
+
+        When the `acme` `certificateScheme` is selected, you can use this option
+        to override the default certificate name. This is useful if you've
+        generated a wildcard certificate, for example.
+      '';
+    };
+
     enableImap = mkOption {
       type = types.bool;
-      default = true;
+      default = false;
       description = ''
         Whether to enable IMAP with STARTTLS on port 143.
+
+        The use of this port is deprecated per RFC 8314 4.1.
+      '';
+    };
+
+    imapMemoryLimit = mkOption {
+      type = types.int;
+      default = 256;
+      description = ''
+        The memory limit for the imap service, in megabytes.
       '';
     };
 
@@ -693,9 +903,11 @@ in
 
     enableSubmission = mkOption {
       type = types.bool;
-      default = true;
+      default = false;
       description = ''
         Whether to enable SMTP with STARTTLS on port 587.
+
+        The use of this port is discouraged per RFC 8314 3.3, see also Appendix A.
       '';
     };
 
@@ -712,6 +924,8 @@ in
       default = false;
       description = ''
         Whether to enable POP3 with STARTTLS on port on port 110.
+
+        The use of this port is deprecated per RFC 8314 4.1.
       '';
     };
 
@@ -776,11 +990,27 @@ in
       '';
     };
 
+    dkimKeyType = mkOption {
+      type = types.enum [
+        "rsa"
+        "ed25519"
+      ];
+      default = "rsa";
+      description = ''
+        The key type used for generating DKIM keys. ED25519 was introduced in RFC6376 (2018).
+
+        If you have already deployed a key with a different type than specified
+        here, then you should use a different selector ({option}`mailserver.dkimSelector`). In order to get
+        this package to generate a key with the new type, you will either have to
+        change the selector or delete the old key file.
+      '';
+    };
+
     dkimKeyBits = mkOption {
       type = types.int;
-        default = 1024;
+      default = 2048;
       description = ''
-            How many bits in generated DKIM keys. RFC6376 advises minimum 1024-bit keys.
+        How many bits in generated DKIM keys. RFC8301 suggests a minimum RSA key length of 2048 bit.
 
         If you have already deployed a key with a different number of bits than specified
         here, then you should use a different selector ({option}`mailserver.dkimSelector`). In order to get
@@ -789,26 +1019,6 @@ in
       '';
     };
 
-    dkimHeaderCanonicalization = mkOption {
-        type = types.enum ["relaxed" "simple"];
-        default = "relaxed";
-        description = ''
-          DKIM canonicalization algorithm for message headers.
-
-          See https://datatracker.ietf.org/doc/html/rfc6376/#section-3.4 for details.
-        '';
-    };
-
-    dkimBodyCanonicalization = mkOption {
-        type = types.enum ["relaxed" "simple"];
-        default = "relaxed";
-        description = ''
-          DKIM canonicalization algorithm for message bodies.
-
-          See https://datatracker.ietf.org/doc/html/rfc6376/#section-3.4 for details.
-        '';
-    };
-
     dmarcReporting = {
       enable = mkOption {
         type = types.bool;
@@ -824,62 +1034,47 @@ in
         '';
       };
 
-      localpart = mkOption {
+      excludeDomains = mkOption {
-        type = types.str;
+        type = types.listOf types.str;
-        default = "dmarc-noreply";
+        default = [ ];
-        example = "dmarc-report";
         description = ''
-          The local part of the email address used for outgoing DMARC reports.
+          List of domains or eSLDs to be excluded from DMARC reports.
-        '';
-      };
-
-      domain = mkOption {
-        type = types.enum (cfg.domains);
-        example = "example.com";
-        description = ''
-          The domain from which outgoing DMARC reports are served.
-        '';
-      };
-
-      email = mkOption {
-        type = types.str;
-        default = with cfg.dmarcReporting; "${localpart}@${domain}";
-        defaultText = literalExpression ''"''${localpart}@''${domain}"'';
-        readOnly = true;
-        description = ''
-          The email address used for outgoing DMARC reports. Read-only.
-        '';
-      };
-
-      organizationName = mkOption {
-        type = types.str;
-        example = "ACME Corp.";
-        description = ''
-          The name of your organization used in the `org_name` attribute in
-          DMARC reports.
-        '';
-      };
-
-      fromName = mkOption {
-        type = types.str;
-        default = cfg.dmarcReporting.organizationName;
-        defaultText = literalMD "{option}`mailserver.dmarcReporting.organizationName`";
-        description = ''
-          The sender name for DMARC reports. Defaults to the organization name.
         '';
       };
     };
 
-    debug = mkOption {
+    tlsrpt.enable = mkEnableOption "delivery of SMTP TLS reports according to RFC 8460";
+
+    debug = {
+      all = mkOption {
         type = types.bool;
         default = false;
         description = ''
-        Whether to enable verbose logging for mailserver related services. This
+          Whether to enable verbose logging for all mailserver related services.
-        intended be used for development purposes only, you probably don't want
+          This intended be used for development purposes only, you probably
-        to enable this unless you're hacking on nixos-mailserver.
+          don't want to enable this unless you're hacking on nixos-mailserver.
         '';
       };
 
+      dovecot = mkOption {
+        type = types.bool;
+        default = cfg.debug.all;
+        defaultText = lib.literalExpression "config.mailserver.debug.all";
+        description = ''
+          Whether to enable verbose logging for Dovecot.
+        '';
+      };
+
+      rspamd = mkOption {
+        type = types.bool;
+        default = cfg.debug.all;
+        defaultText = lib.literalExpression "config.mailserver.debug.all";
+        description = ''
+          Whether to enable verbose logging for Rspamd.
+        '';
+      };
+    };
+
     maxConnectionsPerUser = mkOption {
       type = types.int;
       default = 100;
@@ -906,39 +1101,60 @@ in
       '';
     };
 
+    srs = {
+      enable = mkEnableOption "Sender Rewrite Scheme";
+
+      domain = mkOption {
+        type = with types; nullOr str;
+        default = config.mailserver.systemDomain;
+        defaultText = literalExpression "config.mailserver.systemDomain";
+        example = "srs.example.com";
+        description = ''
+          Mail domain used for ephemeral SRS envelope addresses.
+
+          :::{note}
+          This domain can only support relaxed SPF alignment.
+          :::
+
+          :::{important}
+          For privacy reasons you should use a dedicated domain when serving multiple unrelated domains.
+          :::
+        '';
+      };
+    };
+
     redis = {
+      configureLocally = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Whether to provision a local Redis instance.
+        '';
+      };
+
       address = mkOption {
         type = types.str;
         # read the default from nixos' redis module
-        default = let
+        default = config.services.redis.servers.rspamd.unixSocket;
-          cf = config.services.redis.servers.rspamd.bind;
+        defaultText = literalExpression "config.services.redis.servers.rspamd.unixSocket";
-          cfdefault = if cf == null then "127.0.0.1" else cf;
-          ips = lib.strings.splitString " " cfdefault;
-          ip = lib.lists.head (ips ++ [ "127.0.0.1" ]);
-          isIpv6 = ip: lib.lists.elem ":" (lib.stringToCharacters ip);
-        in
-        if (ip == "0.0.0.0" || ip == "::")
-        then "127.0.0.1"
-        else if isIpv6 ip then "[${ip}]" else ip;
-        defaultText = lib.literalMD "computed from `config.services.redis.servers.rspamd.bind`";
         description = ''
-          Address that rspamd should use to contact redis.
+          Path, IP address or hostname that Rspamd should use to contact Redis.
         '';
       };
 
       port = mkOption {
-        type = types.port;
+        type = with types; nullOr port;
-        default = config.services.redis.servers.rspamd.port;
+        default = null;
-        defaultText = lib.literalExpression "config.services.redis.servers.rspamd.port";
+        example = literalExpression "config.services.redis.servers.rspamd.port";
         description = ''
-          Port that rspamd should use to contact redis.
+          Port that Rspamd should use to contact Redis.
         '';
       };
 
       password = mkOption {
         type = types.nullOr types.str;
         default = config.services.redis.servers.rspamd.requirePass;
-        defaultText = lib.literalExpression "config.services.redis.servers.rspamd.requirePass";
+        defaultText = literalExpression "config.services.redis.servers.rspamd.requirePass";
         description = ''
           Password that rspamd should use to contact redis, or null if not required.
         '';
@@ -955,25 +1171,10 @@ in
       '';
     };
 
-    smtpdForbidBareNewline = mkOption {
-      type = types.bool;
-      default = true;
-      description = ''
-        With "smtpd_forbid_bare_newline = yes", the Postfix SMTP server
-        disconnects a remote SMTP client that sends a line ending in a 'bare
-        newline'.
-
-        This feature was added in Postfix 3.8.4 against SMTP Smuggling and will
-        default to "yes" in Postfix 3.9.
-
-        https://www.postfix.org/smtp-smuggling.html
-      '';
-    };
-
     sendingFqdn = mkOption {
       type = types.str;
       default = cfg.fqdn;
-      defaultText = lib.literalMD "{option}`mailserver.fqdn`";
+      defaultText = literalMD "{option}`mailserver.fqdn`";
       example = "myserver.example.com";
       description = ''
         The fully qualified domain name of the mail server used to
@@ -997,18 +1198,6 @@ in
       '';
     };
 
-    policydSPFExtraConfig = mkOption {
-      type = types.lines;
-      default = "";
-      example = ''
-        skip_addresses = 127.0.0.0/8,::ffff:127.0.0.0/104,::1
-      '';
-      description = ''
-        Extra configuration options for policyd-spf. This can be use to among
-        other things skip spf checking for some IP addresses.
-      '';
-    };
-
     monitoring = {
       enable = mkEnableOption "monitoring via monit";
 
@@ -1061,7 +1250,7 @@ in
                 start program = "${pkgs.systemd}/bin/systemctl start rspamd"
                 stop program = "${pkgs.systemd}/bin/systemctl stop rspamd"
         '';
-        defaultText = lib.literalMD "see [source](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/blob/master/default.nix)";
+        defaultText = literalMD "see [source](https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/blob/master/default.nix)";
         description = ''
           The configuration used for monitoring via monit.
           Use a mail address that you actively check and set it via 'set alert ...'.
@@ -1103,7 +1292,15 @@ in
 
       compression = {
         method = mkOption {
-          type = types.nullOr (types.enum ["none" "lz4" "zstd" "zlib" "lzma"]);
+          type = types.nullOr (
+            types.enum [
+              "none"
+              "lz4"
+              "zstd"
+              "zlib"
+              "lzma"
+            ]
+          );
           default = null;
           description = "Leaving this unset allows borg to choose. The default for borg 1.1.4 is lz4.";
         };
@@ -1162,7 +1359,7 @@ in
       locations = mkOption {
         type = types.listOf types.path;
         default = [ cfg.mailDirectory ];
-        defaultText = lib.literalExpression "[ config.mailserver.mailDirectory ]";
+        defaultText = literalExpression "[ config.mailserver.mailDirectory ]";
         description = "The locations that are to be backed up by borg.";
       };
 
@@ -1202,27 +1399,6 @@ in
 
     };
 
-    rebootAfterKernelUpgrade = {
-      enable = mkOption {
-        type = types.bool;
-        default = false;
-        example = true;
-        description = ''
-          Whether to enable automatic reboot after kernel upgrades.
-          This is to be used in conjunction with `system.autoUpgrade.enable = true;`
-        '';
-      };
-      method = mkOption {
-        type = types.enum [ "reboot" "systemctl kexec" ];
-        default = "reboot";
-        description = ''
-          Whether to issue a full "reboot" or just a "systemctl kexec"-only reboot.
-          It is recommended to use the default value because the quicker kexec reboot has a number of problems.
-          Also if your server is running in a virtual machine the regular reboot will already be very quick.
-        '';
-      };
-    };
-
     backup = {
       enable = mkEnableOption "backup via rsnapshot";
 
@@ -1284,9 +1460,33 @@ in
   };
 
   imports = [
+    (mkRemovedOptionModule [ "mailserver" "fullTextSearch" "maintenance" "enable" ] ''
+      This option is not needed for fts-flatcurve
+    '')
+    (mkRemovedOptionModule [ "mailserver" "fullTextSearch" "maintenance" "onCalendar" ] ''
+      This option is not needed for fts-flatcurve
+    '')
+    (mkRemovedOptionModule [ "mailserver" "fullTextSearch" "maintenance" "randomizedDelaySec" ] ''
+      This option is not needed for fts-flatcurve
+    '')
+    (mkRemovedOptionModule [ "mailserver" "fullTextSearch" "minSize" ] ''
+      This option is not supported by fts-flatcurve
+    '')
+    (mkRemovedOptionModule [ "mailserver" "fullTextSearch" "maxSize" ] ''
+      This option is not needed since fts-xapian 1.8.3
+    '')
+    (mkRemovedOptionModule [ "mailserver" "fullTextSearch" "indexAttachments" ] ''
+      Text attachments are always indexed since fts-xapian 1.4.8
+    '')
+    (mkRenamedOptionModule
+      [ "mailserver" "rebootAfterKernelUpgrade" "enable" ]
+      [ "system" "autoUpgrade" "allowReboot" ]
+    )
+    (mkRemovedOptionModule [ "mailserver" "rebootAfterKernelUpgrade" "method" ] ''
+      Use `system.autoUpgrade` instead.
+    '')
     ./mail-server/assertions.nix
     ./mail-server/borgbackup.nix
-    ./mail-server/debug.nix
     ./mail-server/rsnapshot.nix
     ./mail-server/clamav.nix
     ./mail-server/monit.nix
@@ -1295,11 +1495,36 @@ in
     ./mail-server/networking.nix
     ./mail-server/systemd.nix
     ./mail-server/dovecot.nix
-    ./mail-server/opendkim.nix
     ./mail-server/postfix.nix
     ./mail-server/rspamd.nix
     ./mail-server/nginx.nix
     ./mail-server/kresd.nix
-    ./mail-server/post-upgrade-check.nix
+    (mkRemovedOptionModule [ "mailserver" "policydSPFExtraConfig" ] ''
+      SPF checking has been migrated to Rspamd, which makes this config redundant. Please look into the rspamd config to migrate your settings.
+      It may be that they are redundant and are already configured in rspamd like for skip_addresses.
+    '')
+    (mkRemovedOptionModule [ "mailserver" "dkimHeaderCanonicalization" ] ''
+      DKIM signing has been migrated to Rspamd, which always uses relaxed canonicalization.
+    '')
+    (mkRemovedOptionModule [ "mailserver" "dkimBodyCanonicalization" ] ''
+      DKIM signing has been migrated to Rspamd, which always uses relaxed canonicalization.
+    '')
+    (mkRemovedOptionModule [ "mailserver" "smtpdForbidBareNewline" ] ''
+      The workaround for the SMTP Smuggling attack is default enabled in Postfix >3.9. Use `services.postfix.config.smtpd_forbid_bare_newline` if you need to deviate from its default.
+    '')
+    (mkRenamedOptionModule [ "mailserver" "dmarcReporting" "domain" ] [ "mailserver" "systemDomain" ])
+    (mkRenamedOptionModule
+      [ "mailserver" "dmarcReporting" "organizationName" ]
+      [ "mailserver" "systemName" ]
+    )
+    (mkRemovedOptionModule [ "mailserver" "dmarcReporting" "localpart" ] ''
+      The localpart is now fixed at `noreply-dmarc` to simplify the configuration.
+    '')
+    (mkRemovedOptionModule [ "mailserver" "dmarcReporting" "email" ] ''
+      The address is now fixed at `noreply-dmarc@''${config.mailserver.systemDomain}` to simplify the configuration.
+    '')
+    (mkRemovedOptionModule [ "mailserver" "dmarcReporting" "fromName" ] ''
+      The name in the `FROM` field for DMARC report now uses the `mailserver.systemName`.
+    '')
   ];
 }

docs/add-radicale.rst

@@ -24,12 +24,13 @@ have to be used. These can still be generated using `mkpasswd -m bcrypt`.
    in {
      services.radicale = {
        enable = true;
-       config = ''
+       settings = {
-         [auth]
+         auth = {
-         type = htpasswd
+           type = "htpasswd";
-         htpasswd_filename = ${htpasswd}
+           htpasswd_filename = "${htpasswd}";
-         htpasswd_encryption = bcrypt
+           htpasswd_encryption = "bcrypt";
-       '';
+         };
+       };
      };
 
      services.nginx = {

docs/add-roundcube.rst

@@ -20,7 +20,7 @@ servers may require more work.
         extraConfig = ''
           # starttls needed for authentication, so the fqdn required to match
           # the certificate
-          $config['smtp_server'] = "tls://${config.mailserver.fqdn}";
+          $config['smtp_host'] = "tls://${config.mailserver.fqdn}";
           $config['smtp_user'] = "%u";
           $config['smtp_pass'] = "%p";
         '';

docs/advanced-configurations.rst

@@ -0,0 +1,14 @@
+Advanced Configurations
+=======================
+
+Congratulations on completing the `Setup Guide <setup-guide.html>`_!
+
+If you're an experienced mailserver admin, then you probably know what you want
+to do next. Our How-to guides (accessible in the navigation sidebar)
+might help you accomplish your goals. If not, consider contributing a guide!
+
+If this is your first mailserver, consider the following:
+
+- Set up `backups <backup-guide.html>`_.
+- Enable `DMARC reporting <options.html#mailserver-dmarcreporting>`_ to be a
+  good citizen in the mail ecosystem.

docs/backup-guide.rst

@@ -14,6 +14,13 @@ forget to ``chown`` them to ``virtualMail:virtualMail`` if you copy them
 back (or whatever you specified as ``vmailUserName``, and
 ``vmailGoupName``).
 
+If you enabled ``enableManageSieve`` then you also may want to backup
+``/var/sieve`` or whatever you have specified as ``sieveDirectory``.
+The same considerations regarding file ownership apply as for the
+Maildir.
+
+To backup spam and ham training data, backup ``/var/lib/redis-rspamd``.
+
 Finally you can (optionally) make a backup of ``/var/dkim`` (or whatever
 you specified as ``dkimKeyDirectory``). If you should lose those don’t
 worry, new ones will be created on the fly. But you will need to repeat

docs/conf.py

@@ -17,9 +17,9 @@
 
 # -- Project information -----------------------------------------------------
 
-project = 'NixOS Mailserver'
+project = "NixOS Mailserver"
-copyright = '2022, NixOS Mailserver Contributors'
+copyright = "2022, NixOS Mailserver Contributors"
-author = 'NixOS Mailserver Contributors'
+author = "NixOS Mailserver Contributors"
 
 
 # -- General configuration ---------------------------------------------------
@@ -27,33 +27,31 @@ author = 'NixOS Mailserver Contributors'
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
-extensions = [
+extensions = ["myst_parser"]
-    'myst_parser'
-]
 
 myst_enable_extensions = [
-    'colon_fence',
+    "colon_fence",
-    'linkify',
+    "linkify",
 ]
 
 smartquotes = False
 
 # Add any paths that contain templates here, relative to this directory.
-templates_path = ['_templates']
+templates_path = ["_templates"]
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
 # This pattern also affects html_static_path and html_extra_path.
-exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store']
+exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
 
-master_doc = 'index'
+master_doc = "index"
 
 # -- Options for HTML output -------------------------------------------------
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 #
-html_theme = 'sphinx_rtd_theme'
+html_theme = "sphinx_rtd_theme"
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,

docs/flakes.rst

@@ -1,7 +1,7 @@
 Nix Flakes
 ==========
 
-If you're using `flakes <https://nixos.wiki/wiki/Flakes>`__, you can use
+If you're using `flakes <https://wiki.nixos.org/wiki/Flakes>`__, you can use
 the following minimal ``flake.nix`` as an example:
 
 .. code:: nix

docs/fts.rst

@@ -4,7 +4,7 @@ Full text search
 By default, when your IMAP client searches for an email containing some
 text in its *body*, dovecot will read all your email sequentially. This
 is very slow and IO intensive. To speed body searches up, it is possible to
-*index* emails with a plugin to dovecot, ``fts_xapian``.
+*index* emails with a plugin to dovecot, ``fts_flatcurve``.
 
 Enabling full text search
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -20,8 +20,6 @@ To enable indexing for full text search here is an example configuration.
         enable = true;
         # index new email as they arrive
         autoIndex = true;
-        # this only applies to plain text attachments, binary attachments are never indexed
-        indexAttachments = true;
         enforced = "body";
       };
     };
@@ -61,8 +59,8 @@ Mitigating resources requirements
 
 You can:
 
-* disable indexation of attachements ``mailserver.fullTextSearch.indexAttachments = false``
+* exclude some headers from indexation with ``mailserver.fullTextSearch.headerExcludes``
-* reduce the size of ngrams to be indexed ``mailserver.fullTextSearch.minSize`` and ``maxSize``
+* disable expensive token normalisation in ``mailserver.fullTextSearch.filters``
 * disable automatic indexation for some folders with
   ``mailserver.fullTextSearch.autoIndexExclude``.  Folders can be specified by
   name (``"Trash"``), by special use (``"\\Junk"``) or with a wildcard.

docs/howto-develop.rst

@@ -4,13 +4,33 @@ Contribute or troubleshoot
 To report an issue, please go to
 `<https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/issues>`_.
 
-You can also chat with us on the Libera IRC channel ``#nixos-mailserver``.
+If you have questions, feel free to reach out:
+
+* Matrix: `#nixos-mailserver:nixos.org <https://matrix.to/#/#nixos-mailserver:nixos.org>`__
+* IRC: `#nixos-mailserver <ircs://irc.libera.chat/nixos-mailserver>`__ on `Libera Chat <https://libera.chat/guides/connect>`__
+
+All our workflows rely on Nix being configured with `Flakes <https://wiki.nixos.org/wiki/Flakes#Installing_flakes>`__.
+
+Development Shell
+-----------------
+
+We provide a `flake.nix` devshell that automatically sets up pre-commit hooks,
+which allows for fast feedback cycles when making changes to the repository.
+
+
+::
+
+  $ nix develop
+
+
+We recommend setting up `direnv <https://direnv.net/>`__ to automatically
+attach to the development environment when entering the project directories.
 
 Run NixOS tests
 ---------------
 
 To run the test suite, you need to enable `Nix Flakes
-<https://nixos.wiki/wiki/Flakes#Installing_flakes>`_.
+<https://wiki.nixos.org/wiki/Flakes#Installing_flakes>`__.
 
 You can then run the testsuite via
 
@@ -37,7 +57,7 @@ For the syntax, see the `RST/Sphinx primer
 <https://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html>`_.
 
 To build the documentation, you need to enable `Nix Flakes
-<https://nixos.wiki/wiki/Flakes#Installing_flakes>`_.
+<https://wiki.nixos.org/wiki/Flakes#Installing_flakes>`__.
 
 
 ::
@@ -45,28 +65,43 @@ To build the documentation, you need to enable `Nix Flakes
    $ nix build .#documentation
    $ xdg-open result/index.html
 
-Nixops
-------
 
-You can test the setup via ``nixops``. After installation, do
+Manual migrations
+-----------------
 
-::
+We need to take great care around providing a migration story around breaking
+changes. If manual intervention becomes necessary we provide the `stateVersion`
+option to notify the user that they need to complete a migration before
+they can deploy an update.
 
-   $ nixops create nixops/single-server.nix nixops/vbox.nix -d mail
+If that is the case for your change, find the highest `stateVersion` that is
-   $ nixops deploy -d mail
+being asserted on in `mail-server/assertions.nix`. Then pick the next number
-   $ nixops info -d mail
+and add a new assertion, write a good summary describing the issue and what
+remediation steps are necessary. Finally reference the URL to the specific
+section on the migration page in the documentation.
 
-You can then test the server via e.g. \ ``telnet``. To log into it, use
+.. code-block:: nix
 
-::
+  {
+    assertions = [
+      {
+        assertion = config.mailserver.stateVersion != null -> config.mailserver.stateVersion >= 1;
+        message = ''
+          Problem: The home directory for the foobar service is snafu.
+          Remediation:
+            - Stop the `foobar.service`
+            - Rename `/var/lib/foobaz` to `/var/lib/foobar`
+            - Increase the `mailserver.stateVersion` to 1.
 
-   $ nixops ssh -d mail mailserver
+          Check https://nixos-mailserver.readthedocs.io/en/latest/migrations.html#specific-anchor-here for further details.
+        '';
+      }
+    ];
+  }
 
-Imap
+The setup guide should always reference the latest `stateVersion`, since we
-----
+don't require any migration steps for new setups.
 
-To test imap manually use
+The migration documentation should paint a more complete picture about the steps
-
+that need to be carried out and why this has become necessary. Make sure to
-::
+reference the correct anchor in the URL you put into the assertion message.
-
-   $ openssl s_client -host mail.example.com -port 143 -starttls imap

docs/index.rst

@@ -14,23 +14,31 @@ Welcome to NixOS Mailserver's documentation!
    :maxdepth: 2
 
    setup-guide
+   advanced-configurations
    howto-develop
    faq
    release-notes
    options
+   migrations
 
 .. toctree::
    :maxdepth: 1
+   :caption: Features
+
+   fts
+   ldap
+   srs
+
+.. toctree::
+   :maxdepth: 0
    :caption: How-to
 
    backup-guide
    add-radicale
    add-roundcube
    rspamd-tuning
-   fts
    flakes
    autodiscovery
-   ldap
 
 Indices and tables
 ==================

docs/migrations.rst

@@ -0,0 +1,117 @@
+Migrations
+==========
+
+With mail server configuration best practices changing over time we might need
+to make changes that require you to complete manual migration steps before you
+can deploy a new version of NixOS mailserver.
+
+The initial `mailserver.stateVersion` value should be copied from the setup
+guide that you used to initially set up your mail server. If in doubt you can
+always initialize it at `1` and walk through all assertions, that might apply
+to your setup.
+
+NixOS 25.11
+-----------
+
+#3 Dovecot mail directory migration
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The way the Dovecot home directory for login accounts were previously set up
+resulted in shared home directories for all those users. This is not a
+supported Dovecot configuration.
+
+To resolve this we migrated the home directory into the individual
+`domain/localpart` subdirectory below the `mailserver.mailDirectory`.
+
+But since this now overlaps with the location of the Maildir, it must be
+migrated into the `mail/` directory below the home directory.
+And while the LDAP home directory is not affected we use this migration to
+keep the Maildir configurations of LDAP users in sync with those of local
+accounts.
+
+This is a big step forward, since we can now more cleanly colocate other
+data directories, like sieve in the home directory, which in turn simplifies
+backups.
+
+This migration is required for every configuration.
+
+For remediating this issue the following steps are required:
+
+1. Copy the `migration script <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/blob/master/migrations/nixos-mailserver-migration-03.py>`_ script to your mailserver
+   and make it executable:
+
+   .. code-block:: bash
+
+      wcurl https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/raw/master/migrations/nixos-mailserver-migration-03.py
+      chmod +x nixos-mailserver-migration-03.py
+
+2. Stop the ``dovecot2.service``.
+
+   .. code-block:: bash
+
+      systemctl stop dovecot2.service
+
+3. Create a backup or snapshot of your ``mailserver.mailDirectory``, so you can restore
+   should anything go wrong.
+
+4. Run the migration script under your virtual mail user with the following arguments:
+
+   - ``--layout default`` unless ``useFSLayout`` is enabled, then ``--layout folder``
+   - The value of ``mailserver.mailDirectory``, which defaults to ``/var/vmail``
+
+   The script should be run under the user who owns the ``mailDirectory``.
+   If run as root it will try to switch into the appropriate user by itself.
+
+   The script will not modify your data unless called with ``--execute``.
+
+   Example:
+
+   .. code-block:: bash
+
+      ./nixos-mailserver-migration-03.py --layout default /var/vmail
+
+5. Review the commands. They should be
+
+   - create a ``mail`` directory for each accounnt,
+   - move maildir contents from the parent directory into it,
+   - suggest removal of files that do not belong to the maildir
+
+      - their removal is not mandatory and the script **will not** remove them when called with ``--execute``
+      - review these items carefully if you want to remove them yourself
+
+   - remove obsolete files from the old home directory location
+
+6. Rerun the command with ``--execute`` or run the commands manually.
+
+7. Update the ``mailserver.stateVersion`` to ``3``.
+
+#2 Dovecot LDAP home directory migration
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The Dovecot configuration for LDAP home directories previously did not respect
+the ``mailserver.mailDirectory`` setting.
+
+This means that home directories were unconditionally located at
+``/var/vmail/ldap/%{user}``.
+
+This migration is required if you both:
+
+* enabled the LDAP integration (``mailserver.ldap.enable``)
+* and customized the default mail directory (``mailserver.mailDirectory != "/var/vmail"``)
+
+For remediating this issue the following steps are required:
+
+1. Stop ``dovecot2.service``.
+2. Move ``/var/vmail/ldap`` below your ``m̀ailserver.mailDirectory``.
+3. Update the ``mailserver.stateVersion`` to ``2``.
+
+#1 Initialization
+^^^^^^^^^^^^^^^^^
+
+This option was introduced in the NixOS 25.11 release cycle, in which case you
+can safely initialize its value at `1`.
+
+.. code-block:: nix
+
+   mailserver.stateVersion = 1;
+

docs/release-notes.rst

@@ -1,6 +1,94 @@
 Release Notes
 =============
 
+NixOS 25.11
+-----------
+
+- The ``systemName`` and ``systemDomain`` options have been introduced to have
+  reusable configurations for automated reports (DMARC, TLSRPT). They come with
+  reasonable defaults, but it is suggested to check and change them as needed.
+- Support for the `Sender Rewriting Scheme`_ has been added, which allows
+  forwarding mail without breaking SPF by rewriting the envelope address.
+- The default key length for new DKIM RSA keys was increased to 2048 bits as
+  recommended in `RFC 8301 3.2`_.
+  We recommend rotating existing keys, as the RFC advises that signatures from
+  1024 bit keys should not be considered valid any longer.
+- IMAP access over port ``143/tcp`` is now default disabled in line
+  with `RFC 8314 4.1`_. Use IMAP over implicit TLS on port ``993/tcp``
+  instead. If you still require this feature you can reenable it using
+  ``mailserver.enableImap``, but it is scheduled for removal after the 25.11
+  release.
+- SMTP server and client now support and prefer a hybrid key exchange
+  (X25519MLKEM768)
+- SMTP access over STARTTLS on port ``587/tcp`` is now default disabled in line
+  with `RFC 8314 3.3`_. If you still require this feature you can renable it using
+  ``mailserver.enableSubmission``.
+- DMARC reports are now sent with the ``noreply-dmarc`` localpart from the
+  system domain.
+- DANE and MTA-STS are now validated for outgoing SMTP connections using
+  `postfix-tlspol`_.
+- SMTP TLS connection reports (`RFC 8460`_) are now supported using
+  `tlsrpt-reporter`_. They can be enabled with the ``mailserver.tlsrpt.enable``
+  option.
+
+.. _Sender Rewriting Scheme: srs.html
+.. _RFC 8301 3.2: https://www.rfc-editor.org/rfc/rfc8301#section-3.2
+.. _RFC 8314 3.3: https://www.rfc-editor.org/rfc/rfc8314#section-3.3
+.. _RFC 8314 4.1: https://www.rfc-editor.org/rfc/rfc8314#section-4.1
+.. _RFC 8460: https://www.rfc-editor.org/rfc/rfc8460
+.. _postfix-tlspol: https://github.com/Zuplu/postfix-tlspol
+.. _tlsrpt-reporter: https://github.com/sys4/tlsrpt-reporter
+
+NixOS 25.05
+-----------
+
+- OpenDKIM has been removed and DKIM signing is now handled by Rspamd, which only supports ``relaxed`` canoncalizaliaton.
+  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/374>`__)
+- Rspamd now connects to Redis over its Unix Domain Socket by default
+  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/375>`__)
+
+  - If you need to revert TCP connections, configure ``mailserver.redis.address`` to reference the value of ``config.services.redis.servers.rspamd.bind``.
+- The integration with policyd-spf was removed and SPF handling is now fully based on Rspamd scoring.
+  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/380>`__)
+- Switch to the more efficient `fts-flatcurve` indexer for full text search
+  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/361>`__).
+
+  This makes use of a new index, which will be automatically re-generated the
+  next time a folder is searched.
+  The operation is now quick enough to be performed "just-in-time".
+  Alternatively, all indices can be immediately re-generated for all users and
+  folders by running
+
+  .. code-block:: bash
+
+    doveadm fts rescan -u '*' && doveadm index -u '*' -q '*'
+
+  The previous index (which is not automatically discarded to allow rollbacks)
+  can be cleaned up by removing all the `xapian-indexes` directories within
+  ``mailserver.indexDir``.
+- Individual domains can now be excluded from DMARC Reporting through ``mailserver.dmarcReporting.excludedDomains``.
+  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/297>`__)
+- Configuring ``mailserver.forwards`` is now possible when the setup relies on LDAP.
+  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/313>`__)
+- Support for TLS 1.1 was disabled in accordance with `Mozilla's recommendations <https://ssl-config.mozilla.org/#server=postfix>`_.
+  (`merge request <https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/merge_requests/234>`__)
+
+NixOS 24.11
+-----------
+
+- No new feature, only bug fixes and documentation improvements
+
+NixOS 24.05
+-----------
+
+- Add new option ``acmeCertificateName`` which can be used to support
+  wildcard certificates
+
+NixOS 23.11
+-----------
+
+- Add basic support for LDAP users
+- Add support for regex (PCRE) aliases
 
 NixOS 23.05
 -----------
@@ -34,7 +122,6 @@ NixOS 21.11
 - New option ``certificateDomains`` to generate certificate for
   additional domains (such as ``imap.example.com``)
 
-
 NixOS 21.05
 -----------
 

docs/requirements.txt

@@ -2,3 +2,4 @@ sphinx ~= 5.3
 sphinx_rtd_theme ~= 1.1
 myst-parser ~= 0.18
 linkify-it-py ~= 2.0
+standard-imghdr

docs/rspamd-tuning.rst

@@ -24,17 +24,14 @@ You can run the training in a root shell as follows:
 
 .. code:: bash
 
-  # Path to the controller socket
-  export RSOCK="/var/run/rspamd/worker-controller.sock"
-
   # Learn the Junk folder as spam
-  rspamc -h $RSOCK learn_spam /var/vmail/$DOMAIN/$USER/.Junk/cur/
+  rspamc learn_spam /var/vmail/$DOMAIN/$USER/.Junk/cur/
 
   # Learn the INBOX as ham
-  rspamc -h $RSOCK learn_ham /var/vmail/$DOMAIN/$USER/cur/
+  rspamc learn_ham /var/vmail/$DOMAIN/$USER/cur/
 
   # Check that training was successful
-  rspamc -h $RSOCK stat | grep learned
+  rspamc stat | grep learned
 
 Tune symbol weight
 ~~~~~~~~~~~~~~~~~~

docs/setup-guide.rst

@@ -20,25 +20,30 @@ an up and running mail server. Once the server is deployed, we could
 then set all DNS entries required to send and receive mails on this
 server.
 
-Setup DNS A record for server
+Setup DNS A/AAAA records for server
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Add a DNS record to the domain ``example.com`` with the following
+Add DNS records to the domain ``example.com`` with the following
 entries
 
 ==================== ===== ==== =============
 Name (Subdomain)     TTL   Type Value
 ==================== ===== ==== =============
 ``mail.example.com`` 10800 A    ``1.2.3.4``
+``mail.example.com`` 10800 AAAA ``2001::1``
 ==================== ===== ==== =============
 
+If your server does not have an IPv6 address, you must skip the `AAAA` record.
+
 You can check this with
 
 ::
 
-   $ ping mail.example.com
+   $ nix-shell -p bind --command "host -t A mail.example.com"
-   64 bytes from mail.example.com (1.2.3.4): icmp_seq=1 ttl=46 time=21.3 ms
+   mail.example.com has address 1.2.3.4
-   ...
+
+   $ nix-shell -p bind --command "host -t AAAA mail.example.com"
+   mail.example.com has address 2001::1
 
 Note that it can take a while until a DNS entry is propagated. This
 DNS entry is required for the Let's Encrypt certificate generation
@@ -58,15 +63,16 @@ common ones.
      imports = [
        (builtins.fetchTarball {
          # Pick a release version you are interested in and set its hash, e.g.
-         url = "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/nixos-23.05/nixos-mailserver-nixos-23.05.tar.gz";
+         url = "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/nixos-25.11/nixos-mailserver-nixos-25.11.tar.gz";
          # To get the sha256 of the nixos-mailserver tarball, we can use the nix-prefetch-url command:
-         # release="nixos-23.05"; nix-prefetch-url "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/${release}/nixos-mailserver-${release}.tar.gz" --unpack
+         # release="nixos-25.11"; nix-prefetch-url "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/${release}/nixos-mailserver-${release}.tar.gz" --unpack
          sha256 = "0000000000000000000000000000000000000000000000000000";
        })
      ];
 
      mailserver = {
        enable = true;
+       stateVersion = 3;
        fqdn = "mail.example.com";
        domains = [ "example.com" ];
 
@@ -98,8 +104,11 @@ Set rDNS (reverse DNS) entry for server
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Wherever you have rented your server, you should be able to set reverse
-DNS entries for the IP’s you own. Add an entry resolving ``1.2.3.4``
+DNS entries for the IP’s you own:
-to ``mail.example.com``.
+
+- Add an entry resolving IPv4 address ``1.2.3.4`` to ``mail.example.com``.
+- Add an entry resolving IPv6 ``2001::1`` to ``mail.example.com``. Again, this
+  must be skipped if your server does not have an IPv6 address.
 
 .. warning::
 
@@ -115,6 +124,9 @@ You can check this with
    $ nix-shell -p bind --command "host 1.2.3.4"
    4.3.2.1.in-addr.arpa domain name pointer mail.example.com.
 
+   $ nix-shell -p bind --command "host 2001::1"
+   1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1.0.0.2.ip6.arpa domain name pointer mail.example.com.
+
 Note that it can take a while until a DNS entry is propagated.
 
 Set a ``MX`` record
@@ -162,25 +174,26 @@ Note that it can take a while until a DNS entry is propagated.
 Set ``DKIM`` signature
 ^^^^^^^^^^^^^^^^^^^^^^
 
-On your server, the ``opendkim`` systemd service generated a file
+On your server, the ``rspamd`` systemd service generated a file
 containing your DKIM public key in the file
 ``/var/dkim/example.com.mail.txt``. The content of this file looks
 like
 
 ::
 
-   mail._domainkey IN TXT "v=DKIM1; k=rsa; s=email; p=<really-long-key>" ; ----- DKIM mail for domain.tld
+   mail._domainkey	IN	TXT	( "v=DKIM1; k=rsa; "
+      "p=<really-long-key>" )  ; ----- DKIM key mail for nixos.org
 
 where ``really-long-key`` is your public key.
 
 Based on the content of this file, we can add a ``DKIM`` record to the
 domain ``example.com``.
 
-=========================== ===== ==== ==============================
+=========================== ===== ==== ================================================
 Name (Subdomain)            TTL   Type Value
-=========================== ===== ==== ==============================
+=========================== ===== ==== ================================================
-mail._domainkey.example.com 10800 TXT  ``v=DKIM1; p=<really-long-key>``
+mail._domainkey.example.com 10800 TXT  ``v=DKIM1; k=rsa; s=email; p=<really-long-key>``
-=========================== ===== ==== ==============================
+=========================== ===== ==== ================================================
 
 You can check this with
 
@@ -225,3 +238,8 @@ Besides that, you can send an email to
 score, and let `mxtoolbox.com <http://mxtoolbox.com/>`__ take a look at
 your setup, but if you followed the steps closely then everything should
 be awesome!
+
+Next steps (optional)
+~~~~~~~~~~~~~~~~~~~~~
+
+Take a look through our `Advanced Configurations <advanced-configurations.html>`_.

docs/srs.rst

@@ -0,0 +1,102 @@
+Sender Rewriting Scheme
+=======================
+
+The Sender Rewriting Scheme (SRS) allows mail servers to forward emails without
+breaking SPF checks. By rewriting the envelope sender to an address within the
+forwarder’s domain, SRS ensures that forwarded messages pass SPF validation,
+preventing them from being rejected as spoofed or unauthorized.
+
+How SRS works in practice
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+1. ``alice@foo.example`` receives an E-Mail from ``bob@bar.example``. Both the
+envelope sender as well as the ``From`` header show ``bob@bar.example``. This
+results in strict SPF alignment, because ``bar.example`` is the domain used in
+both the ``Return-Path`` and ``FROM`` headers.
+
+2. ``alice@foo.example`` forwards the mail to ``charlie@moo.example`` and
+uses SRS to rewrite the envelope sender to originate from the local SRS domain
+(e.g. `SRS0=HHH=TT=bar.example=alice@foo.example`). The ``FROM`` header remains
+unchanged. This ensures that the forwarded mail succeeds SPF checks.
+
+3. The email reaches ``charlie@moo.example``. SPF passes because the sender
+domain in the envelope has been rewritten. The mismatch between envelope sender
+domain and ``FROM`` domain does however break strict SPF alignment.
+
+Enabling SRS
+~~~~~~~~~~~~
+
+In a simple setup just enabling SRS will use your ``mailserver.systemDomain``
+when rewriting the envelope sender domain.
+
+.. code:: nix
+
+  {
+    mailserver = {
+      srs = {
+        enable = true;
+        #domain = "srs.example.com";
+      };
+    };
+  };
+..
+
+While you can reuse an existing email domain for SRS, it is recommended to
+configure a dedicated SRS domain. This is particularly important under the
+following conditions:
+
+* Multiple unrelated mail domains are hosted on the mailserver
+* The mail domain requires strict SPF alignment in its DMARC policy
+
+Required DNS changes
+~~~~~~~~~~~~~~~~~~~~
+
+.. note::
+  In the following example we assume that you want to set up a dedicated SRS
+  domain. If that is not the case you already have SPF and DKIM set up for the
+  system domain. If you have a DMARC record on the system domain, make sure it
+  uses a relaxed SPF alignment policy (``aspf=r``).
+
+First we set up an MX record. This is so that we can receive and route bounces
+that can result from forwards.
+
+======================== ===== ==== ======== =====================
+Name (Subdomain)         TTL   Type Priority Value
+======================== ===== ==== ======== =====================
+srs.example.com          10800 MX   10       ``mail.example.com``
+======================== ===== ==== ==============================
+
+Next up is the SPF record on the SRS domain to allow SPF authentication.
+
+======================== ===== ==== ===================
+Name (Subdomain)         TTL   Type Value
+======================== ===== ==== ===================
+srs.example.com          10800 TXT  ``v=spf1 mx -all``
+======================== ===== ==== ===================
+
+Then we deploy the DKIM record with the `p=<value>` taken from
+``/var/dkim/srs.example.com.mail.txt``, that appears after deploying with SRS
+enabled.
+
+=============================== ===== ==== ========================================
+Name (Subdomain)                TTL   Type Value
+=============================== ===== ==== ========================================
+mail._domainkey.srs.example.com 10800 TXT  ``v=DKIM1; k=rsa; p=<really-long-key>``
+=============================== ===== ==== ========================================
+
+Finally we can tie this together in the DMARC record to require receivers to
+verify the requested SPF/DKIM alignment.
+
+.. note::
+
+   The SRS domain can only support relaxed SPF alignment due to the envelope
+   sender and ``FROM`` header mismatch.
+
+======================== ===== ==== =========================================
+Name (Subdomain)         TTL   Type Value
+======================== ===== ==== =========================================
+_dmarc.srs.example.com   10800 TXT  ``v=DMARC1; p=reject; aspf=r; adkim=s;``
+======================== ===== ==== =========================================
+
+We can safely configure a ``reject`` policy on the SRS domain, to enforce the
+SPF and DKIM alignment as configured above.

flake.lock

@@ -19,11 +19,11 @@
     "flake-compat": {
       "flake": false,
       "locked": {
-        "lastModified": 1668681692,
+        "lastModified": 1761588595,
-        "narHash": "sha256-Ht91NGdewz8IQLtWZ9LCeNXMSXHUss+9COoqu6JLmXU=",
+        "narHash": "sha256-XKUZz9zewJNUj46b4AJdiRZJAvSZ0Dqj2BNfXvFlJC4=",
         "owner": "edolstra",
         "repo": "flake-compat",
-        "rev": "009399224d5e398d03b22badca40a37ac85412a1",
+        "rev": "f387cd2afec9419c8ee37694406ca490c3f34ee5",
         "type": "github"
       },
       "original": {
@@ -32,74 +32,73 @@
         "type": "github"
       }
     },
+    "git-hooks": {
+      "inputs": {
+        "flake-compat": [
+          "flake-compat"
+        ],
+        "gitignore": "gitignore",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1763319842,
+        "narHash": "sha256-YG19IyrTdnVn0l3DvcUYm85u3PaqBt6tI6VvolcuHnA=",
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "rev": "7275fa67fbbb75891c16d9dee7d88e58aea2d761",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "type": "github"
+      }
+    },
+    "gitignore": {
+      "inputs": {
+        "nixpkgs": [
+          "git-hooks",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1709087332,
+        "narHash": "sha256-HG2cCnktfHsKV0s4XW83gU3F57gaTljL9KNSuG6bnQs=",
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "rev": "637db329424fd7e46cf4185293b9cc8c88c95394",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1670751203,
+        "lastModified": 1764020296,
-        "narHash": "sha256-XdoH1v3shKDGlrwjgrNX/EN8s3c+kQV7xY6cLCE8vcI=",
+        "narHash": "sha256-6zddwDs2n+n01l+1TG6PlyokDdXzu/oBmEejcH5L5+A=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "64e0bf055f9d25928c31fb12924e59ff8ce71e60",
+        "rev": "a320ce8e6e2cc6b4397eef214d202a50a4583829",
         "type": "github"
       },
       "original": {
-        "id": "nixpkgs",
-        "ref": "nixos-unstable",
-        "type": "indirect"
-      }
-    },
-    "nixpkgs-22_11": {
-      "locked": {
-        "lastModified": 1669558522,
-        "narHash": "sha256-yqxn+wOiPqe6cxzOo4leeJOp1bXE/fjPEi/3F/bBHv8=",
         "owner": "NixOS",
+        "ref": "nixos-25.11-small",
         "repo": "nixpkgs",
-        "rev": "ce5fe99df1f15a09a91a86be9738d68fadfbad82",
         "type": "github"
-      },
-      "original": {
-        "id": "nixpkgs",
-        "ref": "nixos-22.11",
-        "type": "indirect"
-      }
-    },
-    "nixpkgs-23_05": {
-      "locked": {
-        "lastModified": 1684782344,
-        "narHash": "sha256-SHN8hPYYSX0thDrMLMWPWYulK3YFgASOrCsIL3AJ78g=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "8966c43feba2c701ed624302b6a935f97bcbdf88",
-        "type": "github"
-      },
-      "original": {
-        "id": "nixpkgs",
-        "ref": "nixos-23.05",
-        "type": "indirect"
       }
     },
     "root": {
       "inputs": {
         "blobs": "blobs",
         "flake-compat": "flake-compat",
-        "nixpkgs": "nixpkgs",
+        "git-hooks": "git-hooks",
-        "nixpkgs-22_11": "nixpkgs-22_11",
+        "nixpkgs": "nixpkgs"
-        "nixpkgs-23_05": "nixpkgs-23_05",
-        "utils": "utils"
-      }
-    },
-    "utils": {
-      "locked": {
-        "lastModified": 1605370193,
-        "narHash": "sha256-YyMTf3URDL/otKdKgtoMChu4vfVL3vCMkRqpGifhUn0=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "5021eac20303a61fafe17224c087f5519baed54d",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
       }
     }
   },

flake.nix

@@ -3,60 +3,80 @@
 
   inputs = {
     flake-compat = {
+      # for shell.nix compat
       url = "github:edolstra/flake-compat";
       flake = false;
     };
-    utils.url = "github:numtide/flake-utils";
+    git-hooks = {
-    nixpkgs.url = "flake:nixpkgs/nixos-unstable";
+      url = "github:cachix/git-hooks.nix";
-    nixpkgs-22_11.url = "flake:nixpkgs/nixos-22.11";
+      inputs.flake-compat.follows = "flake-compat";
-    nixpkgs-23_05.url = "flake:nixpkgs/nixos-23.05";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.11-small";
     blobs = {
       url = "gitlab:simple-nixos-mailserver/blobs";
       flake = false;
     };
   };
 
-  outputs = { self, utils, blobs, nixpkgs, nixpkgs-22_11, nixpkgs-23_05, ... }: let
+  outputs =
+    {
+      self,
+      blobs,
+      git-hooks,
+      nixpkgs,
+      ...
+    }:
+    let
       lib = nixpkgs.lib;
       system = "x86_64-linux";
       pkgs = nixpkgs.legacyPackages.${system};
       releases = [
         {
-        name = "unstable";
+          name = "nixos-25.11";
+          nixpkgs = nixpkgs;
           pkgs = nixpkgs.legacyPackages.${system};
         }
-      {
-        name = "23.05";
-        pkgs = nixpkgs-23_05.legacyPackages.${system};
-      }
       ];
       testNames = [
-      "internal"
-      "external"
         "clamav"
-      "multiple"
+        "external"
+        "internal"
         "ldap"
+        "multiple"
       ];
-    genTest = testName: release: {
+
-      "name"= "${testName}-${builtins.replaceStrings ["."] ["_"] release.name}";
+      genTest =
-      "value"= import (./tests/. + "/${testName}.nix") {
+        testName: release:
+        let
           pkgs = release.pkgs;
-        inherit blobs;
+          nixos-lib = import (release.nixpkgs + "/nixos/lib") {
+            inherit (pkgs) lib;
+          };
+        in
+        {
+          name = "${testName}-${builtins.replaceStrings [ "." ] [ "_" ] release.name}";
+          value = nixos-lib.runTest {
+            hostPkgs = pkgs;
+            imports = [ ./tests/${testName}.nix ];
+            _module.args = { inherit blobs; };
+            extraBaseModules.imports = [ ./default.nix ];
           };
         };
+
       # Generate an attribute set such as
       # {
       #   external-unstable = <derivation>;
       #   external-21_05 = <derivation>;
       #   ...
       # }
-    allTests = lib.listToAttrs (
+      allTests = lib.listToAttrs (lib.flatten (map (t: map (r: genTest t r) releases) testNames));
-      lib.flatten (map (t: map (r: genTest t r) releases) testNames));
 
       mailserverModule = import ./.;
 
       # Generate a MarkDown file describing the options of the NixOS mailserver module
-    optionsDoc = let
+      optionsDoc =
+        let
           eval = lib.evalModules {
             modules = [
               mailserverModule
@@ -64,35 +84,46 @@
                 _module.check = false;
                 mailserver = {
                   fqdn = "mx.example.com";
+                  systemDomain = "example.com";
                   domains = [
                     "example.com"
                   ];
-              dmarcReporting = {
-                organizationName = "Example Corp";
-                domain = "example.com";
-              };
                 };
               }
             ];
           };
-      options = builtins.toFile "options.json" (builtins.toJSON
+          options = builtins.toFile "options.json" (
-        (lib.filter (opt: opt.visible && !opt.internal && lib.head opt.loc == "mailserver")
+            builtins.toJSON (
-          (lib.optionAttrSetToDocList eval.options)));
+              lib.filter (opt: opt.visible && !opt.internal && lib.head opt.loc == "mailserver") (
-    in pkgs.runCommand "options.md" { buildInputs = [pkgs.python3Minimal]; } ''
+                lib.optionAttrSetToDocList eval.options
+              )
+            )
+          );
+        in
+        pkgs.runCommand "options.md" { buildInputs = [ pkgs.python3Minimal ]; } ''
           echo "Generating options.md from ${options}"
           python ${./scripts/generate-options.py} ${options} > $out
+          echo $out
         '';
 
       documentation = pkgs.stdenv.mkDerivation {
         name = "documentation";
-      src = lib.sourceByRegex ./docs ["logo\\.png" "conf\\.py" "Makefile" ".*\\.rst"];
+        src = lib.sourceByRegex ./docs [
-      buildInputs = [(
+          "logo\\.png"
-        pkgs.python3.withPackages (p: with p; [
+          "conf\\.py"
+          "Makefile"
+          ".*\\.rst"
+        ];
+        buildInputs = [
+          (pkgs.python3.withPackages (
+            p: with p; [
               sphinx
-          sphinx_rtd_theme
+              sphinx-rtd-theme
               myst-parser
-        ])
+              linkify-it-py
-      )];
+            ]
+          ))
+        ];
         buildPhase = ''
           cp ${optionsDoc} options.md
           # Workaround for https://github.com/sphinx-doc/sphinx/issues/3451
@@ -104,7 +135,8 @@
         '';
       };
 
-  in {
+    in
+    {
       nixosModules = rec {
         mailserver = mailserverModule;
         default = mailserver;
@@ -112,17 +144,71 @@
       nixosModule = self.nixosModules.default; # compatibility
       hydraJobs.${system} = allTests // {
         inherit documentation;
+        inherit (self.checks.${system}) pre-commit;
+      };
+      checks.${system} = allTests // {
+        pre-commit = git-hooks.lib.${system}.run {
+          src = ./.;
+          hooks = {
+            # docs
+            markdownlint = {
+              enable = true;
+              settings.configuration = {
+                # Max line length, doesn't seem to correclty account for lines containing links
+                # https://github.com/DavidAnson/markdownlint/blob/main/doc/md013.md
+                MD013 = false;
+              };
+            };
+            rstcheck = {
+              enable = true;
+              package = pkgs.rstcheckWithSphinx;
+              entry = lib.getExe pkgs.rstcheckWithSphinx;
+              files = "\\.rst$";
+            };
+
+            # nix
+            deadnix.enable = true;
+            nixfmt-rfc-style.enable = true;
+
+            # python
+            pyright.enable = true;
+            ruff = {
+              enable = true;
+              args = [
+                "--extend-select"
+                "I"
+              ];
+            };
+            ruff-format.enable = true;
+
+            # scripts
+            shellcheck.enable = true;
+
+            # sieve
+            check-sieve = {
+              enable = true;
+              package = pkgs.check-sieve;
+              entry = lib.getExe pkgs.check-sieve;
+              files = "\\.sieve$";
+            };
+          };
+        };
       };
-    checks.${system} = allTests;
       packages.${system} = {
         inherit optionsDoc documentation;
       };
-    devShells.${system}.default = pkgs.mkShell {
+      devShells.${system}.default = pkgs.mkShellNoCC {
         inputsFrom = [ documentation ];
-      packages = with pkgs; [
+        packages =
-        clamav
+          with pkgs;
-      ];
+          [
+            glab
+          ]
+          ++ self.checks.${system}.pre-commit.enabledPackages;
+        shellHook = self.checks.${system}.pre-commit.shellHook;
       };
       devShell.${system} = self.devShells.${system}.default; # compatibility
+
+      formatter.${system} = pkgs.nixfmt-tree;
     };
 }

mail-server/assertions.nix

@@ -1,6 +1,45 @@
-{ config, lib, pkgs, ... }:
 {
-  assertions = lib.optionals config.mailserver.ldap.enable [
+  config,
+  lib,
+  ...
+}:
+
+let
+  mailserverRelease = "25.11";
+  nixpkgsRelease = lib.trivial.release;
+  releaseMismatch =
+    config.mailserver.enableNixpkgsReleaseCheck && mailserverRelease != nixpkgsRelease;
+in
+
+{
+  warnings = lib.optional releaseMismatch ''
+    You are using
+
+      NixOS Mailserver version ${mailserverRelease} and
+      Nixpkgs version ${nixpkgsRelease}.
+
+    Using mismatched versions is likely to cause compatibility issues
+    and may require migrations that make an eventual rollback tricky.
+
+    It is therefore highly recommended to use a release of
+    NixOS mailserver that corresponds with your chosen release of Nixpkgs.
+
+    If you insist then you can disable this warning by adding
+
+      mailserver.enableNixpkgsReleaseCheck = false;
+
+    to your configuration.
+  '';
+
+  # We guard all assertions by requiring mailserver to be actually enabled
+  assertions = lib.optionals config.mailserver.enable (
+    [
+      {
+        assertion = config.mailserver.stateVersion != null;
+        message = "The `mailserver.stateVersion` option is not set. Check https://nixos-mailserver.readthedocs.io/en/latest/migrations.html to determine the proper value to initialize it at.";
+      }
+    ]
+    ++ lib.optionals config.mailserver.ldap.enable [
       {
         assertion = config.mailserver.loginAccounts == { };
         message = "When the LDAP support is enable (mailserver.ldap.enable = true), it is not possible to define mailserver.loginAccounts";
@@ -9,9 +48,38 @@
         assertion = config.mailserver.extraVirtualAliases == { };
         message = "When the LDAP support is enable (mailserver.ldap.enable = true), it is not possible to define mailserver.extraVirtualAliases";
       }
+    ]
+    ++
+      lib.optionals (config.mailserver.ldap.enable && config.mailserver.mailDirectory != "/var/vmail")
+        [
           {
-      assertion = config.mailserver.forwards == {};
+            assertion = config.mailserver.stateVersion != null -> config.mailserver.stateVersion >= 2;
-      message = "When the LDAP support is enable (mailserver.ldap.enable = true), it is not possible to define mailserver.forwards";
+            message = ''
+              Issue: The dovecot homedir for LDAP users was previously not respecting `mailserver.mailDirectory`.
+              Remediation:
+                - Stop the `dovecot2.service`
+                - Move `/var/vmail/ldap` below your `mailserver.mailDirectory`
+                - Increase the `stateVersion` to 2.
+
+              Check https://nixos-mailserver.readthedocs.io/en/latest/migrations.html#dovecot-ldap-home-directory-migration for more information.
+            '';
           }
-  ];
+        ]
+    ++ [
+      {
+        assertion = config.mailserver.stateVersion != null -> config.mailserver.stateVersion >= 3;
+        message = ''
+          Issue: The dovecot mail location for all users has changed and need to be migrated.
+
+          Check https://nixos-mailserver.readthedocs.io/en/latest/migrations.html#dovecot-mail-directory-migration for the required remediation steps.
+        '';
+      }
+    ]
+    ++ lib.optionals (config.mailserver.certificateScheme != "acme") [
+      {
+        assertion = config.mailserver.acmeCertificateName == config.mailserver.fqdn;
+        message = "When the certificate scheme is not 'acme' (mailserver.certificateScheme != \"acme\"), it is not possible to define mailserver.acmeCertificateName";
+      }
+    ]
+  );
 }

mail-server/borgbackup.nix

@@ -14,28 +14,44 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, pkgs, lib, ... }:
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}:
 
 let
   cfg = config.mailserver.borgbackup;
 
   methodFragment = lib.optional (cfg.compression.method != null) cfg.compression.method;
   autoFragment =
-    if cfg.compression.auto && cfg.compression.method == null
+    if cfg.compression.auto && cfg.compression.method == null then
-    then throw "compression.method must be set when using auto."
+      throw "compression.method must be set when using auto."
-    else lib.optional cfg.compression.auto "auto";
+    else
+      lib.optional cfg.compression.auto "auto";
   levelFragment =
-    if cfg.compression.level != null && cfg.compression.method == null
+    if cfg.compression.level != null && cfg.compression.method == null then
-    then throw "compression.method must be set when using compression.level."
+      throw "compression.method must be set when using compression.level."
-    else lib.optional (cfg.compression.level != null) (toString cfg.compression.level);
+    else
-  compressionFragment = lib.concatStringsSep "," (lib.flatten [autoFragment methodFragment levelFragment]);
+      lib.optional (cfg.compression.level != null) (toString cfg.compression.level);
+  compressionFragment = lib.concatStringsSep "," (
+    lib.flatten [
+      autoFragment
+      methodFragment
+      levelFragment
+    ]
+  );
   compression = lib.optionalString (compressionFragment != "") "--compression ${compressionFragment}";
 
   encryptionFragment = cfg.encryption.method;
   passphraseFile = lib.escapeShellArg cfg.encryption.passphraseFile;
-  passphraseFragment = lib.optionalString (cfg.encryption.method != "none")
+  passphraseFragment = lib.optionalString (cfg.encryption.method != "none") (
-                         (if cfg.encryption.passphraseFile != null then ''env BORG_PASSPHRASE="$(cat ${passphraseFile})"''
+    if cfg.encryption.passphraseFile != null then
-                          else throw "passphraseFile must be set when using encryption.");
+      ''env BORG_PASSPHRASE="$(cat ${passphraseFile})"''
+    else
+      throw "passphraseFile must be set when using encryption."
+  );
 
   locations = lib.escapeShellArgs cfg.locations;
   name = lib.escapeShellArg cfg.name;
@@ -55,7 +71,8 @@ let
     ${passphraseFragment} ${pkgs.borgbackup}/bin/borg create ${extraCreateArgs} ${compression} ::${name} ${locations}
     ${cmdPostexec}
   '';
-in {
+in
+{
   config = lib.mkIf (config.mailserver.enable && cfg.enable) {
     environment.systemPackages = with pkgs; [
       borgbackup

mail-server/clamav.nix

@@ -14,7 +14,7 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, pkgs, lib, options, ... }:
+{ config, lib, ... }:
 
 let
   cfg = config.mailserver;

mail-server/common.nix

@@ -14,43 +14,63 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, pkgs, lib }:
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}:
 
 let
   cfg = config.mailserver;
 in
 {
   # cert :: PATH
-  certificatePath = if cfg.certificateScheme == "manual"
+  certificatePath =
-             then cfg.certificateFile
+    if cfg.certificateScheme == "manual" then
-             else if cfg.certificateScheme == "selfsigned"
+      cfg.certificateFile
-                  then "${cfg.certificateDirectory}/cert-${cfg.fqdn}.pem"
+    else if cfg.certificateScheme == "selfsigned" then
-                  else if cfg.certificateScheme == "acme" || cfg.certificateScheme == "acme-nginx"
+      "${cfg.certificateDirectory}/cert-${cfg.fqdn}.pem"
-                       then "${config.security.acme.certs.${cfg.fqdn}.directory}/fullchain.pem"
+    else if cfg.certificateScheme == "acme" || cfg.certificateScheme == "acme-nginx" then
-                       else throw "unknown certificate scheme";
+      "${config.security.acme.certs.${cfg.acmeCertificateName}.directory}/fullchain.pem"
+    else
+      throw "unknown certificate scheme";
 
   # key :: PATH
-  keyPath = if cfg.certificateScheme == "manual"
+  keyPath =
-        then cfg.keyFile
+    if cfg.certificateScheme == "manual" then
-        else if cfg.certificateScheme == "selfsigned"
+      cfg.keyFile
-             then "${cfg.certificateDirectory}/key-${cfg.fqdn}.pem"
+    else if cfg.certificateScheme == "selfsigned" then
-              else if cfg.certificateScheme == "acme" || cfg.certificateScheme == "acme-nginx"
+      "${cfg.certificateDirectory}/key-${cfg.fqdn}.pem"
-                   then "${config.security.acme.certs.${cfg.fqdn}.directory}/key.pem"
+    else if cfg.certificateScheme == "acme" || cfg.certificateScheme == "acme-nginx" then
-                   else throw "unknown certificate scheme";
+      "${config.security.acme.certs.${cfg.acmeCertificateName}.directory}/key.pem"
+    else
+      throw "unknown certificate scheme";
 
-  passwordFiles = let
+  passwordFiles =
+    let
       mkHashFile = name: hash: pkgs.writeText "${builtins.hashString "sha256" name}-password-hash" hash;
     in
-    lib.mapAttrs (name: value:
+    lib.mapAttrs (
+      name: value:
       if value.hashedPasswordFile == null then
         builtins.toString (mkHashFile name value.hashedPassword)
-    else value.hashedPasswordFile) cfg.loginAccounts;
+      else
+        value.hashedPasswordFile
+    ) cfg.loginAccounts;
 
   # Appends the LDAP bind password to files to avoid writing this
   # password into the Nix store.
-  appendLdapBindPwd = {
+  appendLdapBindPwd =
-    name, file, prefix, passwordFile, destination
+    {
-  }: pkgs.writeScript "append-ldap-bind-pwd-in-${name}" ''
+      name,
+      file,
+      prefix,
+      suffix ? "",
+      passwordFile,
+      destination,
+    }:
+    pkgs.writeScript "append-ldap-bind-pwd-in-${name}" ''
       #!${pkgs.stdenv.shell}
       set -euo pipefail
 
@@ -61,8 +81,9 @@ in
       fi
 
       cat ${file} > ${destination}
-    echo -n "${prefix}" >> ${destination}
+      echo -n '${prefix}' >> ${destination}
-    cat ${passwordFile} >> ${destination}
+      cat ${passwordFile} | tr -d '\n' >> ${destination}
+      echo -n '${suffix}' >> ${destination}
       chmod 600 ${destination}
     '';
 

mail-server/debug.nix

@@ -1,4 +0,0 @@
-{ config, lib, ... }:
-{
-  mailserver.policydSPFExtraConfig = lib.mkIf config.mailserver.debug "debugLevel = 4";
-}

mail-server/dovecot.nix

@@ -14,9 +14,22 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, pkgs, lib, ... }:
+{
+  config,
+  options,
+  pkgs,
+  lib,
+  ...
+}:
 
-with (import ./common.nix { inherit config pkgs lib; });
+with (import ./common.nix {
+  inherit
+    config
+    options
+    pkgs
+    lib
+    ;
+});
 
 let
   cfg = config.mailserver;
@@ -26,40 +39,27 @@ let
   userdbFile = "${passwdDir}/userdb";
   # This file contains the ldap bind password
   ldapConfFile = "${passwdDir}/dovecot-ldap.conf.ext";
-  bool2int = x: if x then "1" else "0";
+  boolToYesNo = x: if x then "yes" else "no";
+  listToLine = lib.concatStringsSep " ";
+  listToMultiAttrs =
+    keyPrefix: attrs:
+    lib.listToAttrs (
+      lib.imap1 (n: x: {
+        name = "${keyPrefix}${if n == 1 then "" else toString n}";
+        value = x;
+      }) attrs
+    );
 
   maildirLayoutAppendix = lib.optionalString cfg.useFsLayout ":LAYOUT=fs";
   maildirUTF8FolderNames = lib.optionalString cfg.useUTF8FolderNames ":UTF-8";
 
-  # maildir in format "/${domain}/${user}"
+  # https://doc.dovecot.org/2.3/configuration_manual/home_directories_for_virtual_users/#ways-to-set-up-home-directory
+  # Mail directory below the home directory
   dovecotMaildir =
-    "maildir:${cfg.mailDirectory}/%d/%n${maildirLayoutAppendix}${maildirUTF8FolderNames}"
+    "maildir:~/mail${maildirLayoutAppendix}${maildirUTF8FolderNames}"
-    + (lib.optionalString (cfg.indexDir != null)
+    + (lib.optionalString (cfg.indexDir != null) ":INDEX=${cfg.indexDir}/%{domain}/%{username}");
-       ":INDEX=${cfg.indexDir}/%d/%n"
-      );
 
   postfixCfg = config.services.postfix;
-  dovecot2Cfg = config.services.dovecot2;
-
-  stateDir = "/var/lib/dovecot";
-
-  pipeBin = pkgs.stdenv.mkDerivation {
-    name = "pipe_bin";
-    src = ./dovecot/pipe_bin;
-    buildInputs = with pkgs; [ makeWrapper coreutils bash rspamd ];
-    buildCommand = ''
-      mkdir -p $out/pipe/bin
-      cp $src/* $out/pipe/bin/
-      chmod a+x $out/pipe/bin/*
-      patchShebangs $out/pipe/bin
-
-      for file in $out/pipe/bin/*; do
-        wrapProgram $file \
-          --set PATH "${pkgs.coreutils}/bin:${pkgs.rspamd}/bin"
-      done
-    '';
-  };
-
 
   ldapConfig = pkgs.writeTextFile {
     name = "dovecot-ldap.conf.ext.template";
@@ -76,7 +76,7 @@ let
       auth_bind = yes
       base = ${cfg.ldap.searchBase}
       scope = ${mkLdapSearchScope cfg.ldap.searchScope}
-      ${lib.optionalString (cfg.ldap.dovecot.userAttrs != "") ''
+      ${lib.optionalString (cfg.ldap.dovecot.userAttrs != null) ''
         user_attrs = ${cfg.ldap.dovecot.userAttrs}
       ''}
       user_filter = ${cfg.ldap.dovecot.userFilter}
@@ -90,7 +90,8 @@ let
   setPwdInLdapConfFile = appendLdapBindPwd {
     name = "ldap-conf-file";
     file = ldapConfig;
-    prefix = "dnpass = ";
+    prefix = ''dnpass = "'';
+    suffix = ''"'';
     passwordFile = cfg.ldap.bind.passwordFile;
     destination = ldapConfFile;
   };
@@ -108,7 +109,9 @@ let
     # Prevent world-readable password files, even temporarily.
     umask 077
 
-    for f in ${builtins.toString (lib.mapAttrsToList (name: value: passwordFiles."${name}") cfg.loginAccounts)}; do
+    for f in ${
+      builtins.toString (lib.mapAttrsToList (name: _: passwordFiles."${name}") cfg.loginAccounts)
+    }; do
       if [ ! -f "$f" ]; then
         echo "Expected password hash file $f does not exist!"
         exit 1
@@ -116,35 +119,61 @@ let
     done
 
     cat <<EOF > ${passwdFile}
-    ${lib.concatStringsSep "\n" (lib.mapAttrsToList (name: value:
+    ${lib.concatStringsSep "\n" (
-      "${name}:${"$(head -n 1 ${passwordFiles."${name}"})"}::::::"
+      lib.mapAttrsToList (
-    ) cfg.loginAccounts)}
+        name: _: "${name}:${"$(head -n 1 ${passwordFiles."${name}"})"}::::::"
+      ) cfg.loginAccounts
+    )}
     EOF
 
     cat <<EOF > ${userdbFile}
-    ${lib.concatStringsSep "\n" (lib.mapAttrsToList (name: value:
+    ${lib.concatStringsSep "\n" (
+      lib.mapAttrsToList (
+        name: value:
         "${name}:::::::"
-        + (if lib.isString value.quota
+        + lib.optionalString (value.quota != null) "userdb_quota_rule=*:storage=${value.quota}"
-              then "userdb_quota_rule=*:storage=${value.quota}"
+      ) cfg.loginAccounts
-              else "")
+    )}
-    ) cfg.loginAccounts)}
     EOF
   '';
 
-  junkMailboxes = builtins.attrNames (lib.filterAttrs (n: v: v ? "specialUse" && v.specialUse == "Junk") cfg.mailboxes);
+  junkMailboxes = builtins.attrNames (
+    lib.filterAttrs (_: v: v ? "specialUse" && v.specialUse == "Junk") cfg.mailboxes
+  );
   junkMailboxNumber = builtins.length junkMailboxes;
   # The assertion garantees there is exactly one Junk mailbox.
   junkMailboxName = if junkMailboxNumber == 1 then builtins.elemAt junkMailboxes 0 else "";
 
-  mkLdapSearchScope = scope: (
+  mkLdapSearchScope =
-    if scope == "sub" then "subtree"
+    scope:
-    else if scope == "one" then "onelevel"
+    (
-    else scope
+      if scope == "sub" then
+        "subtree"
+      else if scope == "one" then
+        "onelevel"
+      else
+        scope
     );
 
+  ftsPluginSettings = {
+    fts = "flatcurve";
+    fts_languages = listToLine cfg.fullTextSearch.languages;
+    fts_tokenizers = listToLine [
+      "generic"
+      "email-address"
+    ];
+    fts_tokenizer_email_address = "maxlen=100"; # default 254 too large for Xapian
+    fts_flatcurve_substring_search = boolToYesNo cfg.fullTextSearch.substringSearch;
+    fts_filters = listToLine cfg.fullTextSearch.filters;
+    fts_header_excludes = listToLine cfg.fullTextSearch.headerExcludes;
+    fts_autoindex = boolToYesNo cfg.fullTextSearch.autoIndex;
+    fts_enforced = cfg.fullTextSearch.enforced;
+  }
+  // (listToMultiAttrs "fts_autoindex_exclude" cfg.fullTextSearch.autoIndexExclude);
+
 in
 {
-  config = with cfg; lib.mkIf enable {
+  config = lib.mkIf cfg.enable {
     assertions = [
       {
         assertion = junkMailboxNumber == 1;
@@ -152,31 +181,64 @@ in
       }
     ];
 
+    warnings =
+      lib.optional
+        (
+          (builtins.length cfg.fullTextSearch.languages > 1)
+          && (builtins.elem "stopwords" cfg.fullTextSearch.filters)
+        )
+        ''
+          Using stopwords in `mailserver.fullTextSearch.filters` with multiple
+          languages in `mailserver.fullTextSearch.languages` configured WILL
+          cause some searches to fail.
+
+          The recommended solution is to NOT use the stopword filter when
+          multiple languages are present in the configuration.
+        '';
+
     # for sieve-test. Shelling it in on demand usually doesnt' work, as it reads
     # the global config and tries to open shared libraries configured in there,
     # which are usually not compatible.
     environment.systemPackages = [
       pkgs.dovecot_pigeonhole
-    ];
+    ]
+    ++ lib.optional cfg.fullTextSearch.enable pkgs.dovecot-fts-flatcurve;
+
+    # For compatibility with python imaplib
+    environment.etc."dovecot/modules".source = "/run/current-system/sw/lib/dovecot/modules";
 
     services.dovecot2 = {
       enable = true;
-      enableImap = enableImap || enableImapSsl;
+      enableImap = cfg.enableImap || cfg.enableImapSsl;
-      enablePop3 = enablePop3 || enablePop3Ssl;
+      enablePop3 = cfg.enablePop3 || cfg.enablePop3Ssl;
       enablePAM = false;
       enableQuota = true;
-      mailGroup = vmailGroupName;
+      mailGroup = cfg.vmailGroupName;
-      mailUser = vmailUserName;
+      mailUser = cfg.vmailUserName;
       mailLocation = dovecotMaildir;
       sslServerCert = certificatePath;
       sslServerKey = keyPath;
+      enableDHE = lib.mkDefault false;
       enableLmtp = true;
-      modules = [ pkgs.dovecot_pigeonhole ] ++ (lib.optional cfg.fullTextSearch.enable pkgs.dovecot_fts_xapian );
+      mailPlugins.globally.enable = lib.optionals cfg.fullTextSearch.enable [
-      mailPlugins.globally.enable = lib.optionals cfg.fullTextSearch.enable [ "fts" "fts_xapian" ];
+        "fts"
+        "fts_flatcurve"
+      ];
       protocols = lib.optional cfg.enableManageSieve "sieve";
 
-      sieveScripts = {
+      pluginSettings = {
-        after = builtins.toFile "spam.sieve" ''
+        sieve = "file:${cfg.sieveDirectory}/%{user}/scripts;active=${cfg.sieveDirectory}/%{user}/active.sieve";
+        sieve_default = "file:${cfg.sieveDirectory}/%{user}/default.sieve";
+        sieve_default_name = "default";
+      }
+      // (lib.optionalAttrs cfg.fullTextSearch.enable ftsPluginSettings);
+
+      sieve = {
+        extensions = [
+          "fileinto"
+        ];
+
+        scripts.after = builtins.toFile "spam.sieve" ''
           require "fileinto";
 
           if header :is "X-Spam" "Yes" {
@@ -184,13 +246,35 @@ in
               stop;
           }
         '';
+
+        pipeBins = map lib.getExe [
+          (pkgs.writeShellScriptBin "rspamd-learn-ham.sh" "exec ${pkgs.rspamd}/bin/rspamc -h /run/rspamd/worker-controller.sock learn_ham")
+          (pkgs.writeShellScriptBin "rspamd-learn-spam.sh" "exec ${pkgs.rspamd}/bin/rspamc -h /run/rspamd/worker-controller.sock learn_spam")
+        ];
       };
 
+      imapsieve.mailbox = [
+        {
+          name = junkMailboxName;
+          causes = [
+            "COPY"
+            "APPEND"
+          ];
+          before = ./dovecot/imap_sieve/report-spam.sieve;
+        }
+        {
+          name = "*";
+          from = junkMailboxName;
+          causes = [ "COPY" ];
+          before = ./dovecot/imap_sieve/report-ham.sieve;
+        }
+      ];
+
       mailboxes = cfg.mailboxes;
 
       extraConfig = ''
         #Extra Config
-        ${lib.optionalString debug ''
+        ${lib.optionalString cfg.debug.dovecot ''
           mail_debug = yes
           auth_debug = yes
           verbose_ssl = yes
@@ -199,42 +283,62 @@ in
         ${lib.optionalString (cfg.enableImap || cfg.enableImapSsl) ''
           service imap-login {
             inet_listener imap {
-              ${if cfg.enableImap then ''
+              ${
+                if cfg.enableImap then
+                  ''
                     port = 143
-              '' else ''
+                  ''
+                else
+                  ''
                     # see https://dovecot.org/pipermail/dovecot/2010-March/047479.html
                     port = 0
-              ''}
+                  ''
+              }
             }
             inet_listener imaps {
-              ${if cfg.enableImapSsl then ''
+              ${
+                if cfg.enableImapSsl then
+                  ''
                     port = 993
                     ssl = yes
-              '' else ''
+                  ''
+                else
+                  ''
                     # see https://dovecot.org/pipermail/dovecot/2010-March/047479.html
                     port = 0
-              ''}
+                  ''
+              }
             }
           }
         ''}
         ${lib.optionalString (cfg.enablePop3 || cfg.enablePop3Ssl) ''
           service pop3-login {
             inet_listener pop3 {
-              ${if cfg.enablePop3 then ''
+              ${
+                if cfg.enablePop3 then
+                  ''
                     port = 110
-              '' else ''
+                  ''
+                else
+                  ''
                     # see https://dovecot.org/pipermail/dovecot/2010-March/047479.html
                     port = 0
-              ''}
+                  ''
+              }
             }
             inet_listener pop3s {
-              ${if cfg.enablePop3Ssl then ''
+              ${
+                if cfg.enablePop3Ssl then
+                  ''
                     port = 995
                     ssl = yes
-              '' else ''
+                  ''
+                else
+                  ''
                     # see https://dovecot.org/pipermail/dovecot/2010-March/047479.html
                     port = 0
-              ''}
+                  ''
+              }
             }
           }
         ''}
@@ -244,14 +348,21 @@ in
           mail_plugins = $mail_plugins imap_sieve
         }
 
+        service imap {
+          vsz_limit = ${builtins.toString cfg.imapMemoryLimit} MB
+        }
+
         protocol pop3 {
           mail_max_userip_connections = ${toString cfg.maxConnectionsPerUser}
         }
 
-        mail_access_groups = ${vmailGroupName}
+        mail_access_groups = ${cfg.vmailGroupName}
+
+        # https://ssl-config.mozilla.org/#server=dovecot&version=2.3.21&config=intermediate&openssl=3.4.1&guideline=5.7
         ssl = required
-        ssl_min_protocol = TLSv1.2
+        ssl_min_protocol = TLSv1
-        ssl_prefer_server_ciphers = yes
+        ssl_prefer_server_ciphers = no
+        ssl_curve_list = X25519MLKEM768:X25519:prime256v1:secp384r1
 
         service lmtp {
           unix_listener dovecot-lmtp {
@@ -259,6 +370,17 @@ in
             mode = 0600
             user = ${postfixCfg.user}
           }
+          vsz_limit = ${builtins.toString cfg.lmtpMemoryLimit} MB
+        }
+
+        service quota-status {
+          inet_listener {
+            port = 0
+          }
+          unix_listener quota-status {
+            user = postfix
+          }
+          vsz_limit = ${builtins.toString cfg.quotaStatusMemoryLimit} MB
         }
 
         recipient_delimiter = ${cfg.recipientDelimiter}
@@ -276,7 +398,10 @@ in
         userdb {
           driver = passwd-file
           args = ${userdbFile}
-          default_fields = uid=${builtins.toString cfg.vmailUID} gid=${builtins.toString cfg.vmailUID} home=${cfg.mailDirectory}
+          default_fields = \
+            home=${cfg.mailDirectory}/%{domain}/%{username} \
+            uid=${builtins.toString cfg.vmailUID} \
+            gid=${builtins.toString cfg.vmailUID}
         }
 
         ${lib.optionalString cfg.ldap.enable ''
@@ -288,7 +413,14 @@ in
           userdb {
             driver = ldap
             args = ${ldapConfFile}
-          default_fields = home=/var/vmail/ldap/%u uid=${toString cfg.vmailUID} gid=${toString cfg.vmailUID}
+            default_fields = \
+              home=${cfg.mailDirectory}/ldap/%{user} \
+              uid=${toString cfg.vmailUID} \
+              gid=${toString cfg.vmailUID} \
+              mail=maildir:~/mail${maildirLayoutAppendix}${maildirUTF8FolderNames}${
+                lib.optionalString (cfg.indexDir != null) ":INDEX=${cfg.indexDir}/ldap/%{user}"
+              }
+
           }
         ''}
 
@@ -307,90 +439,27 @@ in
           inbox = yes
         }
 
-        plugin {
-          sieve_plugins = sieve_imapsieve sieve_extprograms
-          sieve = file:${cfg.sieveDirectory}/%u/scripts;active=${cfg.sieveDirectory}/%u/active.sieve
-          sieve_default = file:${cfg.sieveDirectory}/%u/default.sieve
-          sieve_default_name = default
-
-          # From elsewhere to Spam folder
-          imapsieve_mailbox1_name = ${junkMailboxName}
-          imapsieve_mailbox1_causes = COPY,APPEND
-          imapsieve_mailbox1_before = file:${stateDir}/imap_sieve/report-spam.sieve
-
-          # From Spam folder to elsewhere
-          imapsieve_mailbox2_name = *
-          imapsieve_mailbox2_from = ${junkMailboxName}
-          imapsieve_mailbox2_causes = COPY
-          imapsieve_mailbox2_before = file:${stateDir}/imap_sieve/report-ham.sieve
-
-          sieve_pipe_bin_dir = ${pipeBin}/pipe/bin
-
-          sieve_global_extensions = +vnd.dovecot.pipe +vnd.dovecot.environment
-        }
-
-        ${lib.optionalString cfg.fullTextSearch.enable ''
-        plugin {
-          plugin = fts fts_xapian
-          fts = xapian
-          fts_xapian = partial=${toString cfg.fullTextSearch.minSize} full=${toString cfg.fullTextSearch.maxSize} attachments=${bool2int cfg.fullTextSearch.indexAttachments} verbose=${bool2int cfg.debug}
-
-          fts_autoindex = ${if cfg.fullTextSearch.autoIndex then "yes" else "no"}
-
-          ${lib.strings.concatImapStringsSep "\n" (n: x: "fts_autoindex_exclude${if n==1 then "" else toString n} = ${x}") cfg.fullTextSearch.autoIndexExclude}
-
-          fts_enforced = ${cfg.fullTextSearch.enforced}
-        }
-
-        ${lib.optionalString (cfg.fullTextSearch.memoryLimit != null) ''
         service indexer-worker {
+        ${lib.optionalString (cfg.fullTextSearch.memoryLimit != null) ''
           vsz_limit = ${toString (cfg.fullTextSearch.memoryLimit * 1024 * 1024)}
+        ''}
         }
-        ''}
-        ''}
 
         lda_mailbox_autosubscribe = yes
         lda_mailbox_autocreate = yes
       '';
     };
 
-    systemd.services.dovecot2 = {
+    systemd.services.dovecot = {
       preStart = ''
         ${genPasswdScript}
-        rm -rf '${stateDir}/imap_sieve'
+      ''
-        mkdir '${stateDir}/imap_sieve'
+      + (lib.optionalString cfg.ldap.enable setPwdInLdapConfFile);
-        cp -p "${./dovecot/imap_sieve}"/*.sieve '${stateDir}/imap_sieve/'
-        for k in "${stateDir}/imap_sieve"/*.sieve ; do
-          ${pkgs.dovecot_pigeonhole}/bin/sievec "$k"
-        done
-        chown -R '${dovecot2Cfg.mailUser}:${dovecot2Cfg.mailGroup}' '${stateDir}/imap_sieve'
-      '' + (lib.optionalString cfg.ldap.enable setPwdInLdapConfFile);
     };
 
-    systemd.services.postfix.restartTriggers = [ genPasswdScript ] ++ (lib.optional cfg.ldap.enable [setPwdInLdapConfFile]);
+    systemd.services.postfix.restartTriggers = [
-
+      genPasswdScript
-    systemd.services.dovecot-fts-xapian-optimize = lib.mkIf (cfg.fullTextSearch.enable && cfg.fullTextSearch.maintenance.enable) {
+    ]
-      description = "Optimize dovecot indices for fts_xapian";
+    ++ (lib.optional cfg.ldap.enable [ setPwdInLdapConfFile ]);
-      requisite = [ "dovecot2.service" ];
-      after = [ "dovecot2.service" ];
-      startAt = cfg.fullTextSearch.maintenance.onCalendar;
-      serviceConfig = {
-        Type = "oneshot";
-        ExecStart = "${pkgs.dovecot}/bin/doveadm fts optimize -A";
-        PrivateDevices = true;
-        PrivateNetwork = true;
-        ProtectKernelTunables = true;
-        ProtectKernelModules = true;
-        ProtectControlGroups = true;
-        ProtectHome = true;
-        ProtectSystem = true;
-        PrivateTmp = true;
-      };
-    };
-    systemd.timers.dovecot-fts-xapian-optimize = lib.mkIf (cfg.fullTextSearch.enable && cfg.fullTextSearch.maintenance.enable && cfg.fullTextSearch.maintenance.randomizedDelaySec != 0) {
-      timerConfig = {
-        RandomizedDelaySec = cfg.fullTextSearch.maintenance.randomizedDelaySec;
-      };
-    };
   };
 }

mail-server/dovecot/imap_sieve/report-ham.sieve

@@ -12,4 +12,4 @@ if environment :matches "imap.user" "*" {
   set "username" "${1}";
 }
 
-pipe :copy "sa-learn-ham.sh" [ "${username}" ];
+pipe :copy "rspamd-learn-ham.sh" [ "${username}" ];

mail-server/dovecot/imap_sieve/report-spam.sieve

@@ -4,4 +4,4 @@ if environment :matches "imap.user" "*" {
   set "username" "${1}";
 }
 
-pipe :copy "sa-learn-spam.sh" [ "${username}" ];
+pipe :copy "rspamd-learn-spam.sh" [ "${username}" ];

mail-server/dovecot/pipe_bin/sa-learn-ham.sh

@@ -1,3 +0,0 @@
-#!/bin/bash
-set -o errexit
-exec rspamc -h /run/rspamd/worker-controller.sock learn_ham

mail-server/dovecot/pipe_bin/sa-learn-spam.sh

@@ -1,3 +0,0 @@
-#!/bin/bash
-set -o errexit
-exec rspamc -h /run/rspamd/worker-controller.sock learn_spam

mail-server/environment.nix

@@ -14,15 +14,26 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, pkgs, lib, ... }:
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}:
 
 let
   cfg = config.mailserver;
 in
 {
-  config = with cfg; lib.mkIf enable {
+  config = lib.mkIf cfg.enable {
-    environment.systemPackages = with pkgs; [
+    environment.systemPackages =
-      dovecot opendkim openssh postfix rspamd
+      with pkgs;
-    ] ++ (if certificateScheme == "selfsigned" then [ openssl ] else []);
+      [
+        dovecot
+        openssh
+        postfix
+        rspamd
+      ]
+      ++ (if cfg.certificateScheme == "selfsigned" then [ openssl ] else [ ]);
   };
 }

mail-server/kresd.nix

@@ -14,7 +14,7 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, pkgs, lib, ... }:
+{ config, lib, ... }:
 
 let
   cfg = config.mailserver;
@@ -24,4 +24,3 @@ in
     services.kresd.enable = true;
   };
 }
-

mail-server/monit.nix

@@ -14,7 +14,7 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, pkgs, lib, ... }:
+{ config, lib, ... }:
 
 let
   cfg = config.mailserver;

mail-server/networking.nix

@@ -20,18 +20,20 @@ let
   cfg = config.mailserver;
 in
 {
-  config = with cfg; lib.mkIf (enable && openFirewall) {
+  config = lib.mkIf (cfg.enable && cfg.openFirewall) {
 
     networking.firewall = {
-      allowedTCPPorts = [ 25 ]
+      allowedTCPPorts = [
-        ++ lib.optional enableSubmission 587
+        25
-        ++ lib.optional enableSubmissionSsl 465
+      ]
-        ++ lib.optional enableImap 143
+      ++ lib.optional cfg.enableSubmission 587
-        ++ lib.optional enableImapSsl 993
+      ++ lib.optional cfg.enableSubmissionSsl 465
-        ++ lib.optional enablePop3 110
+      ++ lib.optional cfg.enableImap 143
-        ++ lib.optional enablePop3Ssl 995
+      ++ lib.optional cfg.enableImapSsl 993
-        ++ lib.optional enableManageSieve 4190
+      ++ lib.optional cfg.enablePop3 110
-        ++ lib.optional (certificateScheme == "acme-nginx") 80;
+      ++ lib.optional cfg.enablePop3Ssl 995
+      ++ lib.optional cfg.enableManageSieve 4190
+      ++ lib.optional (cfg.certificateScheme == "acme-nginx") 80;
     };
   };
 }

mail-server/nginx.nix

@@ -14,17 +14,30 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
+{
+  config,
+  options,
+  pkgs,
+  lib,
+  ...
+}:
 
-{ config, pkgs, lib, ... }:
+with (import ./common.nix {
-
+  inherit
-with (import ./common.nix { inherit config; });
+    config
+    options
+    lib
+    pkgs
+    ;
+});
 
 let
   cfg = config.mailserver;
-  acmeRoot = "/var/lib/acme/acme-challenge";
 in
 {
-  config = lib.mkIf (cfg.enable && (cfg.certificateScheme == "acme" || cfg.certificateScheme == "acme-nginx")) {
+  config =
+    lib.mkIf (cfg.enable && (cfg.certificateScheme == "acme" || cfg.certificateScheme == "acme-nginx"))
+      {
         services.nginx = lib.mkIf (cfg.certificateScheme == "acme-nginx") {
           enable = true;
           virtualHosts."${cfg.fqdn}" = {
@@ -32,13 +45,15 @@ in
             serverAliases = cfg.certificateDomains;
             forceSSL = true;
             enableACME = true;
-        acmeRoot = acmeRoot;
           };
         };
 
-    security.acme.certs."${cfg.fqdn}".reloadServices = [
+        security.acme.certs."${cfg.acmeCertificateName}" = {
+          extraDomainNames = lib.mkIf (cfg.certificateScheme == "acme") cfg.certificateDomains;
+          reloadServices = [
             "postfix.service"
-      "dovecot2.service"
+            "dovecot.service"
           ];
         };
+      };
 }

mail-server/opendkim.nix

@@ -1,89 +0,0 @@
-#  nixos-mailserver: a simple mail server
-#  Copyright (C) 2017  Brian Olsen
-#
-#  This program is free software: you can redistribute it and/or modify
-#  it under the terms of the GNU General Public License as published by
-#  the Free Software Foundation, either version 3 of the License, or
-#  (at your option) any later version.
-#
-#  This program is distributed in the hope that it will be useful,
-#  but WITHOUT ANY WARRANTY; without even the implied warranty of
-#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-#  GNU General Public License for more details.
-#
-#  You should have received a copy of the GNU General Public License
-#  along with this program. If not, see <http://www.gnu.org/licenses/>
-{ config, lib, pkgs, ... }:
-
-with lib;
-
-let
-  cfg = config.mailserver;
-
-  dkimUser = config.services.opendkim.user;
-  dkimGroup = config.services.opendkim.group;
-
-  createDomainDkimCert = dom:
-    let
-      dkim_key = "${cfg.dkimKeyDirectory}/${dom}.${cfg.dkimSelector}.key";
-      dkim_txt = "${cfg.dkimKeyDirectory}/${dom}.${cfg.dkimSelector}.txt";
-    in
-        ''
-          if [ ! -f "${dkim_key}" ]
-          then
-              ${pkgs.opendkim}/bin/opendkim-genkey -s "${cfg.dkimSelector}" \
-                                                   -d "${dom}" \
-                                                   --bits="${toString cfg.dkimKeyBits}" \
-                                                   --directory="${cfg.dkimKeyDirectory}"
-              mv "${cfg.dkimKeyDirectory}/${cfg.dkimSelector}.private" "${dkim_key}"
-              mv "${cfg.dkimKeyDirectory}/${cfg.dkimSelector}.txt" "${dkim_txt}"
-              chmod 644 "${dkim_txt}"
-              echo "Generated key for domain ${dom} selector ${cfg.dkimSelector}"
-          fi
-        '';
-  createAllCerts = lib.concatStringsSep "\n" (map createDomainDkimCert cfg.domains);
-
-  keyTable = pkgs.writeText "opendkim-KeyTable"
-    (lib.concatStringsSep "\n" (lib.flip map cfg.domains
-      (dom: "${dom} ${dom}:${cfg.dkimSelector}:${cfg.dkimKeyDirectory}/${dom}.${cfg.dkimSelector}.key")));
-  signingTable = pkgs.writeText "opendkim-SigningTable"
-    (lib.concatStringsSep "\n" (lib.flip map cfg.domains (dom: "${dom} ${dom}")));
-
-  dkim = config.services.opendkim;
-  args = [ "-f" "-l" ] ++ lib.optionals (dkim.configFile != null) [ "-x" dkim.configFile ];
-in
-{
-    config = mkIf (cfg.dkimSigning && cfg.enable) {
-      services.opendkim = {
-        enable = true;
-        selector = cfg.dkimSelector;
-        keyPath = cfg.dkimKeyDirectory;
-        domains = "csl:${builtins.concatStringsSep "," cfg.domains}";
-        configFile = pkgs.writeText "opendkim.conf" (''
-          Canonicalization ${cfg.dkimHeaderCanonicalization}/${cfg.dkimBodyCanonicalization}
-          UMask 0002
-          Socket ${dkim.socket}
-          KeyTable file:${keyTable}
-          SigningTable file:${signingTable}
-        '' + (lib.optionalString cfg.debug ''
-          Syslog yes
-          SyslogSuccess yes
-          LogWhy yes
-        ''));
-      };
-
-      users.users = optionalAttrs (config.services.postfix.user == "postfix") {
-        postfix.extraGroups = [ "${dkimGroup}" ];
-      };
-      systemd.services.opendkim = {
-        preStart = lib.mkForce createAllCerts;
-        serviceConfig = {
-          ExecStart = lib.mkForce "${pkgs.opendkim}/bin/opendkim ${escapeShellArgs args}";
-          PermissionsStartOnly = lib.mkForce false;
-        };
-      };
-      systemd.tmpfiles.rules = [
-        "d '${cfg.dkimKeyDirectory}' - ${dkimUser} ${dkimGroup} - -"
-      ];
-    };
-}

mail-server/post-upgrade-check.nix

@@ -1,46 +0,0 @@
-#  nixos-mailserver: a simple mail server
-#  Copyright (C) 2016-2018  Robin Raymond
-#
-#  This program is free software: you can redistribute it and/or modify
-#  it under the terms of the GNU General Public License as published by
-#  the Free Software Foundation, either version 3 of the License, or
-#  (at your option) any later version.
-#
-#  This program is distributed in the hope that it will be useful,
-#  but WITHOUT ANY WARRANTY; without even the implied warranty of
-#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-#  GNU General Public License for more details.
-#
-#  You should have received a copy of the GNU General Public License
-#  along with this program. If not, see <http://www.gnu.org/licenses/>
-
-{ config, pkgs, lib, ... }:
-
-with lib;
-
-let
-  cfg = config.mailserver;
-in
-{
-  config = mkIf (cfg.enable && cfg.rebootAfterKernelUpgrade.enable) {
-    systemd.services.nixos-upgrade.serviceConfig.ExecStartPost = pkgs.writeScript "post-upgrade-check" ''
-      #!${pkgs.stdenv.shell}
-
-      # Checks whether the "current" kernel is different from the booted kernel
-      # and then triggers a reboot so that the "current" kernel will be the booted one.
-      # This is just an educated guess. If the links do not differ the kernels might still be different, according to spacefrogg in #nixos.
-
-      current=$(readlink -f /run/current-system/kernel)
-      booted=$(readlink -f /run/booted-system/kernel)
-
-      if [ "$current" == "$booted" ]; then
-        echo "kernel version seems unchanged, skipping reboot" | systemd-cat --priority 4 --identifier "post-upgrade-check";
-      else
-        echo "kernel path changed, possibly a new version" | systemd-cat --priority 2 --identifier "post-upgrade-check"
-        echo "$booted" | systemd-cat --priority 2 --identifier "post-upgrade-kernel-check"
-        echo "$current" | systemd-cat --priority 2 --identifier "post-upgrade-kernel-check"
-        ${cfg.rebootAfterKernelUpgrade.method}
-      fi
-    '';
-  };
-}

mail-server/postfix.nix

@@ -14,45 +14,84 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, pkgs, lib, ... }:
+{
+  config,
+  options,
+  pkgs,
+  lib,
+  ...
+}:
 
-with (import ./common.nix { inherit config pkgs lib; });
+with (import ./common.nix {
+  inherit
+    config
+    options
+    lib
+    pkgs
+    ;
+});
 
 let
   inherit (lib.strings) concatStringsSep;
   cfg = config.mailserver;
 
+  iniFormat = pkgs.formats.iniWithGlobalSection { };
+
   # Merge several lookup tables. A lookup table is a attribute set where
   # - the key is an address (user@example.com) or a domain (@example.com)
   # - the value is a list of addresses
-  mergeLookupTables = tables: lib.zipAttrsWith (n: v: lib.flatten v) tables;
+  mergeLookupTables = tables: lib.zipAttrsWith (_: v: lib.flatten v) tables;
 
   # valiases_postfix :: Map String [String]
-  valiases_postfix = mergeLookupTables (lib.flatten (lib.mapAttrsToList
+  valiases_postfix = mergeLookupTables (
-    (name: value:
+    lib.flatten (
-      let to = name;
+      lib.mapAttrsToList (
-      in map (from: {"${from}" = to;}) (value.aliases ++ lib.singleton name))
+        name: value:
-    cfg.loginAccounts));
+        let
-  regex_valiases_postfix = mergeLookupTables (lib.flatten (lib.mapAttrsToList
+          to = name;
-    (name: value:
+        in
-      let to = name;
+        map (from: { "${from}" = to; }) (value.aliases ++ lib.singleton name)
-      in map (from: {"${from}" = to;}) value.aliasesRegexp)
+      ) cfg.loginAccounts
-    cfg.loginAccounts));
+    )
+  );
+  regex_valiases_postfix = mergeLookupTables (
+    lib.flatten (
+      lib.mapAttrsToList (
+        name: value:
+        let
+          to = name;
+        in
+        map (from: { "${from}" = to; }) value.aliasesRegexp
+      ) cfg.loginAccounts
+    )
+  );
 
   # catchAllPostfix :: Map String [String]
-  catchAllPostfix =  mergeLookupTables (lib.flatten (lib.mapAttrsToList
+  catchAllPostfix = mergeLookupTables (
-    (name: value:
+    lib.flatten (
-      let to = name;
+      lib.mapAttrsToList (
-      in map (from: {"@${from}" = to;}) value.catchAll)
+        name: value:
-      cfg.loginAccounts));
+        let
+          to = name;
+        in
+        map (from: { "@${from}" = to; }) value.catchAll
+      ) cfg.loginAccounts
+    )
+  );
 
   # all_valiases_postfix :: Map String [String]
-  all_valiases_postfix = mergeLookupTables [valiases_postfix extra_valiases_postfix];
+  all_valiases_postfix = mergeLookupTables [
+    valiases_postfix
+    extra_valiases_postfix
+  ];
 
   # attrsToLookupTable :: Map String (Either String [ String ]) -> Map String [String]
-  attrsToLookupTable = aliases: let
+  attrsToLookupTable =
+    aliases:
+    let
       lookupTables = lib.mapAttrsToList (from: to: { "${from}" = to; }) aliases;
-  in mergeLookupTables lookupTables;
+    in
+    mergeLookupTables lookupTables;
 
   # extra_valiases_postfix :: Map String [String]
   extra_valiases_postfix = attrsToLookupTable cfg.extraVirtualAliases;
@@ -61,37 +100,49 @@ let
   forwards = attrsToLookupTable cfg.forwards;
 
   # lookupTableToString :: Map String [String] -> String
-  lookupTableToString = attrs: let
+  lookupTableToString =
+    attrs:
+    let
       valueToString = value: lib.concatStringsSep ", " value;
-  in lib.concatStringsSep "\n" (lib.mapAttrsToList (name: value: "${name} ${valueToString value}") attrs);
+    in
+    lib.concatStringsSep "\n" (
+      lib.mapAttrsToList (name: value: "${name} ${valueToString value}") attrs
+    );
 
   # valiases_file :: Path
-  valiases_file = let
+  valiases_file =
-    content = lookupTableToString (mergeLookupTables [all_valiases_postfix catchAllPostfix]);
+    let
-  in builtins.toFile "valias" content;
+      content = lookupTableToString (mergeLookupTables [
+        all_valiases_postfix
+        catchAllPostfix
+      ]);
+    in
+    builtins.toFile "valias" content;
 
-  regex_valiases_file = let
+  regex_valiases_file =
+    let
       content = lookupTableToString regex_valiases_postfix;
-  in builtins.toFile "regex_valias" content;
+    in
+    builtins.toFile "regex_valias" content;
 
   # denied_recipients_postfix :: [ String ]
-  denied_recipients_postfix = (map
+  denied_recipients_postfix = map (acct: "${acct.name} REJECT ${acct.sendOnlyRejectMessage}") (
-    (acct: "${acct.name} REJECT ${acct.sendOnlyRejectMessage}")
+    lib.filter (acct: acct.sendOnly) (lib.attrValues cfg.loginAccounts)
-    (lib.filter (acct: acct.sendOnly) (lib.attrValues cfg.loginAccounts)));
+  );
-  denied_recipients_file = builtins.toFile "denied_recipients" (lib.concatStringsSep "\n" denied_recipients_postfix);
+  denied_recipients_file = builtins.toFile "denied_recipients" (
+    lib.concatStringsSep "\n" denied_recipients_postfix
+  );
 
-  reject_senders_postfix = (map
+  reject_senders_postfix = map (sender: "${sender} REJECT") cfg.rejectSender;
-    (sender:
+  reject_senders_file = builtins.toFile "reject_senders" (
-      "${sender} REJECT")
+    lib.concatStringsSep "\n" reject_senders_postfix
-    (cfg.rejectSender));
+  );
-  reject_senders_file = builtins.toFile "reject_senders" (lib.concatStringsSep "\n" (reject_senders_postfix))  ;
 
-  reject_recipients_postfix = (map
+  reject_recipients_postfix = map (recipient: "${recipient} REJECT") cfg.rejectRecipients;
-    (recipient:
-      "${recipient} REJECT")
-    (cfg.rejectRecipients));
   # rejectRecipients :: [ Path ]
-  reject_recipients_file = builtins.toFile "reject_recipients" (lib.concatStringsSep "\n" (reject_recipients_postfix))  ;
+  reject_recipients_file = builtins.toFile "reject_recipients" (
+    lib.concatStringsSep "\n" reject_recipients_postfix
+  );
 
   # vhosts_file :: Path
   vhosts_file = builtins.toFile "vhosts" (concatStringsSep "\n" cfg.domains);
@@ -103,9 +154,12 @@ let
   # every alias is owned (uniquely) by its user.
   # The user's own address is already in all_valiases_postfix.
   vaccounts_file = builtins.toFile "vaccounts" (lookupTableToString all_valiases_postfix);
-  regex_vaccounts_file = builtins.toFile "regex_vaccounts" (lookupTableToString regex_valiases_postfix);
+  regex_vaccounts_file = builtins.toFile "regex_vaccounts" (
+    lookupTableToString regex_valiases_postfix
+  );
 
-  submissionHeaderCleanupRules = pkgs.writeText "submission_header_cleanup_rules" (''
+  submissionHeaderCleanupRules = pkgs.writeText "submission_header_cleanup_rules" (
+    ''
       # Removes sensitive headers from mails handed in via the submission port.
       # See https://thomas-leister.de/mailserver-debian-stretch/
       # Uses "pcre" style regex.
@@ -115,28 +169,22 @@ let
       /^X-Mailer:/            IGNORE
       /^User-Agent:/          IGNORE
       /^X-Enigmail:/          IGNORE
-  '' + lib.optionalString cfg.rewriteMessageId ''
+    ''
+    + lib.optionalString cfg.rewriteMessageId ''
 
       # Replaces the user submitted hostname with the server's FQDN to hide the
       # user's host or network.
 
       /^Message-ID:\s+<(.*?)@.*?>/ REPLACE Message-ID: <$1@${cfg.fqdn}>
-  '');
+    ''
+  );
 
-  inetSocket = addr: port: "inet:[${toString port}@${addr}]";
+  smtpdMilters = [ "unix:/run/rspamd/rspamd-milter.sock" ];
-  unixSocket = sock: "unix:${sock}";
-
-  smtpdMilters =
-   (lib.optional cfg.dkimSigning "unix:/run/opendkim/opendkim.sock")
-   ++ [ "unix:/run/rspamd/rspamd-milter.sock" ];
-
-  policyd-spf = pkgs.writeText "policyd-spf.conf" cfg.policydSPFExtraConfig;
 
   mappedFile = name: "hash:/var/lib/postfix/conf/${name}";
   mappedRegexFile = name: "pcre:/var/lib/postfix/conf/${name}";
 
-  submissionOptions =
+  submissionOptions = {
-    {
     smtpd_tls_security_level = "encrypt";
     smtpd_sasl_auth_enable = "yes";
     smtpd_sasl_type = "dovecot";
@@ -144,7 +192,9 @@ let
     smtpd_sasl_security_options = "noanonymous";
     smtpd_sasl_local_domain = "$myhostname";
     smtpd_client_restrictions = "permit_sasl_authenticated,reject";
-      smtpd_sender_login_maps = "hash:/etc/postfix/vaccounts${lib.optionalString cfg.ldap.enable ",ldap:${ldapSenderLoginMapFile}"}${lib.optionalString (regex_valiases_postfix != {}) ",pcre:/etc/postfix/regex_vaccounts"}";
+    smtpd_sender_login_maps = "hash:/etc/postfix/vaccounts${lib.optionalString cfg.ldap.enable ",ldap:${ldapSenderLoginMapFile}"}${
+      lib.optionalString (regex_valiases_postfix != { }) ",pcre:/etc/postfix/regex_vaccounts"
+    }";
     smtpd_sender_restrictions = "reject_sender_login_mismatch";
     smtpd_recipient_restrictions = "reject_non_fqdn_recipient,reject_unknown_recipient_domain,permit_sasl_authenticated,reject";
     cleanup_service_name = "submission-header-cleanup";
@@ -193,20 +243,55 @@ let
   };
 in
 {
-  config = with cfg; lib.mkIf enable {
+  config = lib.mkIf cfg.enable {
+    # SMTP TLS error reporting (RFC 8460)
+    services.tlsrpt = {
+      inherit (cfg.tlsrpt) enable;
+      configurePostfix = true;
+      reportd.settings = {
+        organization_name = cfg.systemName;
+        contact_info = "${cfg.systemContact}";
+        sender_address = "noreply-tlsrpt@${cfg.systemDomain}";
+      };
+    };
+
+    # SMTP client policy mapping for DANE (RFC 6698) and MTA-STS (RFC 8461)
+    services.postfix-tlspol = {
+      enable = true;
+      configurePostfix = true;
+    };
+
+    # Sender Rewriting Scheme (https://www.libsrs2.net/srs/srs.pdf)
+    services.postsrsd = {
+      inherit (cfg.srs) enable;
+      configurePostfix = true;
+      settings = {
+        domains = lib.unique (
+          [
+            cfg.fqdn
+            cfg.sendingFqdn
+            cfg.systemDomain
+          ]
+          ++ cfg.domains
+        );
+        separator = "=";
+        srs-domain = cfg.srs.domain;
+      };
+    };
 
     systemd.services.postfix-setup = lib.mkIf cfg.ldap.enable {
       preStart = ''
         ${appendPwdInVirtualMailboxMap}
         ${appendPwdInSenderLoginMap}
       '';
-      restartTriggers = [ appendPwdInVirtualMailboxMap appendPwdInSenderLoginMap ];
+      restartTriggers = [
+        appendPwdInVirtualMailboxMap
+        appendPwdInSenderLoginMap
+      ];
     };
 
     services.postfix = {
       enable = true;
-      hostname = "${sendingFqdn}";
-      networksStyle = "host";
       mapFiles."valias" = valiases_file;
       mapFiles."regex_valias" = regex_valiases_file;
       mapFiles."vaccounts" = vaccounts_file;
@@ -214,36 +299,43 @@ in
       mapFiles."denied_recipients" = denied_recipients_file;
       mapFiles."reject_senders" = reject_senders_file;
       mapFiles."reject_recipients" = reject_recipients_file;
-      sslCert = certificatePath;
-      sslKey = keyPath;
       enableSubmission = cfg.enableSubmission;
       enableSubmissions = cfg.enableSubmissionSsl;
-      virtual = lookupTableToString (mergeLookupTables [all_valiases_postfix catchAllPostfix forwards]);
+      virtual = lookupTableToString (mergeLookupTables [
+        all_valiases_postfix
+        catchAllPostfix
+        forwards
+      ]);
 
-      config = {
+      settings.main = {
-        # Extra Config
+        myhostname = cfg.sendingFqdn;
-        mydestination = "";
+        mydestination = ""; # disable local mail delivery
         recipient_delimiter = cfg.recipientDelimiter;
-        smtpd_banner = "${fqdn} ESMTP NO UCE";
+        smtpd_banner = "${cfg.fqdn} ESMTP NO UCE";
         disable_vrfy_command = true;
-        message_size_limit = toString cfg.messageSizeLimit;
+        message_size_limit = cfg.messageSizeLimit;
 
         # virtual mail system
         virtual_uid_maps = "static:5000";
         virtual_gid_maps = "static:5000";
-        virtual_mailbox_base = mailDirectory;
+        virtual_mailbox_base = cfg.mailDirectory;
         virtual_mailbox_domains = vhosts_file;
         virtual_mailbox_maps = [
           (mappedFile "valias")
-        ] ++ lib.optionals (cfg.ldap.enable) [
+        ]
+        ++ lib.optionals cfg.ldap.enable [
           "ldap:${ldapVirtualMailboxMapFile}"
-        ] ++ lib.optionals (regex_valiases_postfix != {}) [
+        ]
+        ++ lib.optionals (regex_valiases_postfix != { }) [
           (mappedRegexFile "regex_valias")
         ];
-        virtual_alias_maps = lib.mkAfter (lib.optionals (regex_valiases_postfix != {}) [
+        virtual_alias_maps = lib.mkAfter (
+          lib.optionals (regex_valiases_postfix != { }) [
             (mappedRegexFile "regex_valias")
-        ]);
+          ]
+        );
         virtual_transport = "lmtp:unix:/run/dovecot2/dovecot-lmtp";
+
         # Avoid leakage of X-Original-To, X-Delivered-To headers between recipients
         lmtp_destination_recipient_limit = "1";
 
@@ -252,91 +344,125 @@ in
         smtpd_sasl_path = "/run/dovecot2/auth";
         smtpd_sasl_auth_enable = true;
         smtpd_relay_restrictions = [
-          "permit_mynetworks" "permit_sasl_authenticated" "reject_unauth_destination"
+          "permit_mynetworks"
+          "permit_sasl_authenticated"
+          "reject_unauth_destination"
         ];
 
-        policy-spf_time_limit = "3600s";
-
         # reject selected senders
         smtpd_sender_restrictions = [
           "check_sender_access ${mappedFile "reject_senders"}"
         ];
 
-        # quota and spf checking
         smtpd_recipient_restrictions = [
+          # reject selected recipients
           "check_recipient_access ${mappedFile "denied_recipients"}"
           "check_recipient_access ${mappedFile "reject_recipients"}"
-          "check_policy_service inet:localhost:12340"
+          # quota checking
-          "check_policy_service unix:private/policy-spf"
+          "check_policy_service unix:/run/dovecot2/quota-status"
         ];
 
-        # TLS settings, inspired by https://github.com/jeaye/nix-files
+        # The X509 private key followed by the corresponding certificate
-        # Submission by mail clients is handled in submissionOptions
+        smtpd_tls_chain_files = [
+          "${keyPath}"
+          "${certificatePath}"
+        ];
+
+        # TLS for incoming mail is optional
         smtpd_tls_security_level = "may";
 
-        # strong might suffice and is computationally less expensive
+        # But required for authentication attempts
-        smtpd_tls_eecdh_grade = "ultra";
+        smtpd_tls_auth_only = true;
 
-        # Disable obselete protocols
+        # TLS versions supported for the SMTP server
-        smtpd_tls_protocols = "TLSv1.3, TLSv1.2, TLSv1.1, !TLSv1, !SSLv2, !SSLv3";
+        smtpd_tls_protocols = ">=TLSv1";
-        smtp_tls_protocols = "TLSv1.3, TLSv1.2, TLSv1.1, !TLSv1, !SSLv2, !SSLv3";
+        smtpd_tls_mandatory_protocols = ">=TLSv1";
-        smtpd_tls_mandatory_protocols = "TLSv1.3, TLSv1.2, TLSv1.1, !TLSv1, !SSLv2, !SSLv3";
-        smtp_tls_mandatory_protocols = "TLSv1.3, TLSv1.2, TLSv1.1, !TLSv1, !SSLv2, !SSLv3";
 
-        smtp_tls_ciphers = "high";
+        # Require ciphersuites that OpenSSL classifies as "High"
         smtpd_tls_ciphers = "high";
-        smtp_tls_mandatory_ciphers = "high";
         smtpd_tls_mandatory_ciphers = "high";
 
-        # Disable deprecated ciphers
+        # Exclude cipher suites with undesirable properties
-        smtpd_tls_mandatory_exclude_ciphers = "MD5, DES, ADH, RC4, PSD, SRP, 3DES, eNULL, aNULL";
+        smtpd_tls_exclude_ciphers = "SHA1, eNULL, aNULL";
-        smtpd_tls_exclude_ciphers = "MD5, DES, ADH, RC4, PSD, SRP, 3DES, eNULL, aNULL";
+        smtpd_tls_mandatory_exclude_ciphers = "SHA1, eNULL, aNULL";
-        smtp_tls_mandatory_exclude_ciphers = "MD5, DES, ADH, RC4, PSD, SRP, 3DES, eNULL, aNULL";
-        smtp_tls_exclude_ciphers = "MD5, DES, ADH, RC4, PSD, SRP, 3DES, eNULL, aNULL";
 
-        tls_preempt_cipherlist = true;
+        # Enable DNSSEC/DANE support for outgoing SMTP connections
+        # https://www.postfix.org/postconf.5.html#smtp_tls_security_level
+        smtp_dns_support_level = "dnssec";
+        smtp_tls_security_level = "dane";
+
+        # TLS versions supported for the SMTP client
+        smtp_tls_protocols = ">=TLSv1.2";
+        smtp_tls_mandatory_protocols = ">=TLSv1.2";
+
+        # Require ciphersuites that OpenSSL classifies as "High"
+        smtp_tls_ciphers = "high";
+        smtp_tls_mandatory_ciphers = "high";
+
+        # Exclude ciphersuites with undesirable properties
+        smtp_tls_exclude_ciphers = "SHA1, eNULL, aNULL";
+        smtp_tls_mandatory_exclude_ciphers = "SHA1, eNULL, aNULL";
+
+        # Restrict and prioritize the following curves in the given order
+        # Excludes curves that have no widespread support, so we don't bloat the handshake needlessly.
+        # https://www.postfix.org/postconf.5.html#tls_eecdh_auto_curves
+        tls_config_file =
+          let
+            mkGroupString = groups: concatStringsSep " / " (map (concatStringsSep ":") groups);
+          in
+          iniFormat.generate "postfix-openssl.cnf" {
+            globalSection.postfix = "postfix_settings";
+            sections = {
+              postfix_settings.ssl_conf = "postfix_ssl_settings";
+              postfix_ssl_settings.system_default = "baseline_postfix_settings";
+              baseline_postfix_settings.Groups = mkGroupString [
+                [ "*X25519MLKEM768" ]
+                [ "*X25519" ]
+                [
+                  "P-256"
+                  "P-384"
+                ]
+              ];
+            };
+          };
+        tls_config_name = "postfix";
+
+        # Algorithm selection happens through `tls_config_file` instead.
+        tls_eecdh_auto_curves = [ ];
+        tls_ffdhe_auto_groups = [ ];
+
+        # As long as all cipher suites are considered safe, let the client use its preferred cipher
+        tls_preempt_cipherlist = false;
 
-        # Allowing AUTH on a non encrypted connection poses a security risk
-        smtpd_tls_auth_only = true;
         # Log only a summary message on TLS handshake completion
+        smtp_tls_loglevel = "1";
         smtpd_tls_loglevel = "1";
 
-        # Configure a non blocking source of randomness
-        tls_random_source = "dev:/dev/urandom";
-
         smtpd_milters = smtpdMilters;
-        non_smtpd_milters = lib.mkIf cfg.dkimSigning ["unix:/run/opendkim/opendkim.sock"];
+        non_smtpd_milters = lib.mkIf cfg.dkimSigning [ "unix:/run/rspamd/rspamd-milter.sock" ];
         milter_protocol = "6";
-        milter_mail_macros = "i {mail_addr} {client_addr} {client_name} {auth_type} {auth_authen} {auth_author} {mail_addr} {mail_host} {mail_mailer}";
+        milter_mail_macros = "i {mail_addr} {client_addr} {client_name} {auth_authen}";
-
-        # Fix for https://www.postfix.org/smtp-smuggling.html
-        smtpd_forbid_bare_newline = cfg.smtpdForbidBareNewline;
-        smtpd_forbid_bare_newline_exclusions = "$mynetworks";
       };
 
       submissionOptions = submissionOptions;
       submissionsOptions = submissionOptions;
 
-      masterConfig = {
+      settings.master = {
         "lmtp" = {
           # Add headers when delivering, see http://www.postfix.org/smtp.8.html
           # D => Delivered-To, O => X-Original-To, R => Return-Path
           args = [ "flags=O" ];
         };
-        "policy-spf" = {
-          type = "unix";
-          privileged = true;
-          chroot = false;
-          command = "spawn";
-          args = [ "user=nobody" "argv=${pkgs.pypolicyd-spf}/bin/policyd-spf" "${policyd-spf}"];
-        };
         "submission-header-cleanup" = {
           type = "unix";
           private = false;
           chroot = false;
           maxproc = 0;
           command = "cleanup";
-          args = ["-o" "header_checks=pcre:${submissionHeaderCleanupRules}"];
+          args = [
+            "-o"
+            "header_checks=pcre:${submissionHeaderCleanupRules}"
+          ];
         };
       };
     };

mail-server/rsnapshot.nix

@@ -14,11 +14,19 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, pkgs, lib, ... }:
+{
-
+  config,
-with lib;
+  pkgs,
+  lib,
+  ...
+}:
 
 let
+  inherit (lib)
+    optionalString
+    mkIf
+    ;
+
   cfg = config.mailserver;
 
   preexecDefined = cfg.backup.cmdPreexec != null;
@@ -38,7 +46,8 @@ let
     ${cfg.backup.cmdPostexec}
   '';
   postexecString = optionalString postexecDefined "cmd_postexec	${postexecWrapped}";
-in {
+in
+{
   config = mkIf (cfg.enable && cfg.backup.enable) {
     services.rsnapshot = {
       enable = true;

mail-server/rspamd.nix

@@ -14,7 +14,12 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, pkgs, lib, ... }:
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}:
 
 let
   cfg = config.mailserver;
@@ -22,27 +27,77 @@ let
   postfixCfg = config.services.postfix;
   rspamdCfg = config.services.rspamd;
   rspamdSocket = "rspamd.service";
+
+  rspamdUser = config.services.rspamd.user;
+  rspamdGroup = config.services.rspamd.group;
+
+  createDkimKeypair =
+    domain:
+    let
+      privateKey = "${cfg.dkimKeyDirectory}/${domain}.${cfg.dkimSelector}.key";
+      publicKey = "${cfg.dkimKeyDirectory}/${domain}.${cfg.dkimSelector}.txt";
+    in
+    pkgs.writeShellScript "dkim-keygen-${domain}" ''
+      if [ ! -f "${privateKey}" ]
+      then
+        ${lib.getExe' pkgs.rspamd "rspamadm"} dkim_keygen \
+          --domain "${domain}" \
+          --selector "${cfg.dkimSelector}" \
+          --type "${cfg.dkimKeyType}" \
+          --bits ${toString cfg.dkimKeyBits} \
+          --privkey "${privateKey}" > "${publicKey}"
+        chmod 0644 "${publicKey}"
+        echo "Generated key for domain ${domain} and selector ${cfg.dkimSelector}"
+      fi
+    '';
+
+  dkimDomains = lib.unique (cfg.domains ++ (lib.optionals cfg.srs.enable [ cfg.srs.domain ]));
 in
 {
-  config = with cfg; lib.mkIf enable {
+  config = lib.mkIf cfg.enable {
+    environment.systemPackages = lib.mkBefore [
+      (pkgs.runCommand "rspamc-wrapped"
+        {
+          nativeBuildInputs = with pkgs; [ makeWrapper ];
+        }
+        ''
+          makeWrapper ${pkgs.rspamd}/bin/rspamc $out/bin/rspamc \
+            --add-flags "-h /run/rspamd/worker-controller.sock"
+        ''
+      )
+    ];
+
     services.rspamd = {
       enable = true;
-      inherit debug;
+      debug = cfg.debug.rspamd;
       locals = {
-          "milter_headers.conf" = { text = ''
+        "milter_headers.conf" = {
-              extended_spam_headers = yes;
+          text = ''
-          ''; };
+            extended_spam_headers = true;
-          "redis.conf" = { text = ''
+          '';
-              servers = "${cfg.redis.address}:${toString cfg.redis.port}";
+        };
-          '' + (lib.optionalString (cfg.redis.password != null) ''
+        "redis.conf" = {
+          text = ''
+            servers = "${
+              if cfg.redis.port == null then
+                cfg.redis.address
+              else
+                "${cfg.redis.address}:${toString cfg.redis.port}"
+            }";
+          ''
+          + (lib.optionalString (cfg.redis.password != null) ''
             password = "${cfg.redis.password}";
-          ''); };
+          '');
-          "classifier-bayes.conf" = { text = ''
+        };
+        "classifier-bayes.conf" = {
+          text = ''
             cache {
               backend = "redis";
             }
-          ''; };
+          '';
-          "antivirus.conf" = lib.mkIf cfg.virusScanning { text = ''
+        };
+        "antivirus.conf" = lib.mkIf cfg.virusScanning {
+          text = ''
             clamav {
               action = "reject";
               symbol = "CLAM_VIRUS";
@@ -51,38 +106,52 @@ in
               servers = "/run/clamav/clamd.ctl";
               scan_mime_parts = false; # scan mail as a whole unit, not parts. seems to be needed to work at all
             }
-          ''; };
+          '';
-          "dkim_signing.conf" = { text = ''
+        };
-              # Disable outbound email signing, we use opendkim for this
+        "dkim_signing.conf" = {
-              enabled = false;
+          text = ''
-          ''; };
+            enabled = ${lib.boolToString cfg.dkimSigning};
-          "dmarc.conf" = { text = ''
+            path = "${cfg.dkimKeyDirectory}/$domain.$selector.key";
+            selector = "${cfg.dkimSelector}";
+            # Allow for usernames w/o domain part
+            allow_username_mismatch = true;
+            # Don't normalize DKIM key selection for subdomains
+            use_esld = false;
+          '';
+        };
+        "dmarc.conf" = {
+          text = ''
             ${lib.optionalString cfg.dmarcReporting.enable ''
               reporting {
                 enabled = true;
-                email = "${cfg.dmarcReporting.email}";
+                email = "noreply-dmarc@${cfg.systemDomain}";
-                domain = "${cfg.dmarcReporting.domain}";
+                domain = "${cfg.systemDomain}";
-                org_name = "${cfg.dmarcReporting.organizationName}";
+                org_name = "${cfg.systemName}";
-                from_name = "${cfg.dmarcReporting.fromName}";
+                from_name = "${cfg.systemName}";
-                msgid_from = "dmarc-rua";
+                msgid_from = "${cfg.systemDomain}";
+                ${lib.optionalString (cfg.dmarcReporting.excludeDomains != [ ]) ''
+                  exclude_domains = ${builtins.toJSON cfg.dmarcReporting.excludeDomains};
+                ''}
               }''}
-          ''; };
+          '';
+        };
       };
-
       overrides = {
-        "milter_headers.conf" = {
+        "options.inc" = {
           text = ''
-            extended_spam_headers = true;
+            local_addrs = [::1/128, 127.0.0.0/8]
           '';
         };
       };
 
       workers.rspamd_proxy = {
         type = "rspamd_proxy";
-        bindSockets = [{
+        bindSockets = [
+          {
             socket = "/run/rspamd/rspamd-milter.sock";
             mode = "0664";
-        }];
+          }
+        ];
         count = 1; # Do not spawn too many processes of this type
         extraConfig = ''
           milter = yes; # Enable milter mode
@@ -97,10 +166,12 @@ in
       workers.controller = {
         type = "controller";
         count = 1;
-        bindSockets = [{
+        bindSockets = [
+          {
             socket = "/run/rspamd/worker-controller.sock";
             mode = "0666";
-        }];
+          }
+        ];
         includes = [ ];
         extraConfig = ''
           static_dir = "''${WWWDIR}"; # Serve the web UI static assets
@@ -109,23 +180,46 @@ in
 
     };
 
-    services.redis.servers.rspamd = {
+    services.redis.servers.rspamd.enable = lib.mkDefault cfg.redis.configureLocally;
-      enable = lib.mkDefault true;
+
-      port = lib.mkDefault 6380;
+    systemd.tmpfiles.settings."10-rspamd.conf" = {
+      "${cfg.dkimKeyDirectory}" = {
+        d = {
+          # Create /var/dkim owned by rspamd user/group
+          user = rspamdUser;
+          group = rspamdGroup;
+        };
+        Z = {
+          # Recursively adjust permissions in /var/dkim
+          user = rspamdUser;
+          group = rspamdGroup;
+        };
+      };
     };
 
     systemd.services.rspamd = {
       requires = [ "redis-rspamd.service" ] ++ (lib.optional cfg.virusScanning "clamav-daemon.service");
       after = [ "redis-rspamd.service" ] ++ (lib.optional cfg.virusScanning "clamav-daemon.service");
+      serviceConfig = lib.mkMerge [
+        {
+          SupplementaryGroups = [ config.services.redis.servers.rspamd.group ];
+        }
+        (lib.optionalAttrs cfg.dkimSigning {
+          ExecStartPre = map createDkimKeypair dkimDomains;
+          ReadWritePaths = [ cfg.dkimKeyDirectory ];
+        })
+      ];
     };
 
-    systemd.services.rspamd-dmarc-reporter = lib.optionalAttrs (cfg.dmarcReporting.enable) {
+    systemd.services.rspamd-dmarc-reporter = lib.optionalAttrs cfg.dmarcReporting.enable {
       # Explicitly select yesterday's date to work around broken
       # default behaviour when called without a date.
       # https://github.com/rspamd/rspamd/issues/4062
-      script = ''
+      script = toString [
-        ${pkgs.rspamd}/bin/rspamadm dmarc_report $(date -d "yesterday" "+%Y%m%d")
+        (lib.getExe' pkgs.rspamd "rspamadm")
-      '';
+        "dmarc_report"
+        "$(date -d 'yesterday' '+%Y%m%d')"
+      ];
       serviceConfig = {
         User = "${config.services.rspamd.user}";
         Group = "${config.services.rspamd.group}";
@@ -151,10 +245,17 @@ in
         ProcSubset = "pid";
         ProtectSystem = "strict";
         RemoveIPC = true;
-        RestrictAddressFamilies = [ "AF_INET" "AF_INET6" ];
+        RestrictAddressFamilies = [
+          "AF_INET"
+          "AF_INET6"
+          "AF_UNIX"
+        ];
         RestrictNamespaces = true;
         RestrictRealtime = true;
         RestrictSUIDSGID = true;
+        SupplementaryGroups = lib.optionals cfg.redis.configureLocally [
+          config.services.redis.servers.rspamd.group
+        ];
         SystemCallArchitectures = "native";
         SystemCallFilter = [
           "@system-service"
@@ -164,7 +265,7 @@ in
       };
     };
 
-    systemd.timers.rspamd-dmarc-reporter = lib.optionalAttrs (cfg.dmarcReporting.enable) {
+    systemd.timers.rspamd-dmarc-reporter = lib.optionalAttrs cfg.dmarcReporting.enable {
       description = "Daily delivery of aggregated DMARC reports";
       wantedBy = [
         "timers.target"
@@ -185,4 +286,3 @@ in
     users.extraUsers.${postfixCfg.user}.extraGroups = [ rspamdCfg.group ];
   };
 }
-

mail-server/systemd.nix

@@ -14,7 +14,22 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, pkgs, lib, ... }:
+{
+  config,
+  options,
+  pkgs,
+  lib,
+  ...
+}:
+
+with (import ./common.nix {
+  inherit
+    config
+    options
+    lib
+    pkgs
+    ;
+});
 
 let
   cfg = config.mailserver;
@@ -25,11 +40,14 @@ let
       [ "mailserver-selfsigned-certificate.service" ]
     else
       [ "acme-finished-${cfg.fqdn}.target" ];
+
 in
 {
-  config = with cfg; lib.mkIf enable {
+  config = lib.mkIf cfg.enable {
     # Create self signed certificate
-    systemd.services.mailserver-selfsigned-certificate = lib.mkIf (cfg.certificateScheme == "selfsigned") {
+    systemd.services.mailserver-selfsigned-certificate =
+      lib.mkIf (cfg.certificateScheme == "selfsigned")
+        {
           after = [ "local-fs.target" ];
           script = ''
             # Create certificates if they do not exist yet
@@ -53,21 +71,22 @@ in
         };
 
     # Create maildir folder before dovecot startup
-    systemd.services.dovecot2 = {
+    systemd.services.dovecot = {
       wants = certificatesDeps;
       after = certificatesDeps;
-      preStart = let
+      preStart =
+        let
           directories = lib.strings.escapeShellArgs (
-          [ mailDirectory ]
+            [ cfg.mailDirectory ] ++ lib.optional (cfg.indexDir != null) cfg.indexDir
-          ++ lib.optional (cfg.indexDir != null) cfg.indexDir
           );
-      in ''
+        in
+        ''
           # Create mail directory and set permissions. See
-        # <http://wiki2.dovecot.org/SharedMailboxes/Permissions>.
+          # <https://doc.dovecot.org/main/core/config/shared_mailboxes.html#filesystem-permissions-1>.
           # Prevent world-readable paths, even temporarily.
           umask 007
           mkdir -p ${directories}
-        chgrp "${vmailGroupName}" ${directories}
+          chgrp "${cfg.vmailGroupName}" ${directories}
           chmod 02770 ${directories}
         '';
     };
@@ -75,11 +94,12 @@ in
     # Postfix requires dovecot lmtp socket, dovecot auth socket and certificate to work
     systemd.services.postfix = {
       wants = certificatesDeps;
-      after = [ "dovecot2.service" ]
+      after = [
-        ++ lib.optional cfg.dkimSigning "opendkim.service"
+        "dovecot.service"
+      ]
+      ++ lib.optional cfg.dkimSigning "rspamd.service"
       ++ certificatesDeps;
-      requires = [ "dovecot2.service" ]
+      requires = [ "dovecot.service" ] ++ lib.optional cfg.dkimSigning "rspamd.service";
-        ++ lib.optional cfg.dkimSigning "opendkim.service";
     };
   };
 }

mail-server/users.nix

@@ -14,7 +14,22 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ config, pkgs, lib, ... }:
+{
+  config,
+  options,
+  pkgs,
+  lib,
+  ...
+}:
+
+with (import ./common.nix {
+  inherit
+    config
+    options
+    lib
+    pkgs
+    ;
+});
 
 with config.mailserver;
 
@@ -28,7 +43,6 @@ let
     group = vmailGroupName;
   };
 
-
   virtualMailUsersActivationScript = pkgs.writeScript "activate-virtual-mail-users" ''
     #!${pkgs.stdenv.shell}
 
@@ -46,8 +60,10 @@ let
 
     # Copy user's sieve script to the correct location (if it exists).  If it
     # is null, remove the file.
-    ${lib.concatMapStringsSep "\n" ({ name, sieveScript }:
+    ${lib.concatMapStringsSep "\n" (
-      if lib.isString sieveScript then ''
+      { name, sieveScript }:
+      if lib.isString sieveScript then
+        ''
           if (! test -d "${sieveDirectory}/${name}"); then
             mkdir -p "${sieveDirectory}/${name}"
             chown "${vmailUserName}:${vmailGroupName}" "${sieveDirectory}/${name}"
@@ -57,34 +73,41 @@ let
           ${sieveScript}
           EOF
           chown "${vmailUserName}:${vmailGroupName}" "${sieveDirectory}/${name}/default.sieve"
-      '' else ''
+        ''
+      else
+        ''
           if (test -f "${sieveDirectory}/${name}/default.sieve"); then
             rm "${sieveDirectory}/${name}/default.sieve"
           fi
           if (test -f "${sieveDirectory}/${name}.svbin"); then
             rm "${sieveDirectory}/${name}/default.svbin"
           fi
-      '') (map (user: { inherit (user) name sieveScript; })
+        ''
-            (lib.attrValues loginAccounts))}
+    ) (map (user: { inherit (user) name sieveScript; }) (lib.attrValues loginAccounts))}
   '';
-in {
+in
+{
   config = lib.mkIf enable {
     # assert that all accounts provide a password
-    assertions = (map (acct: {
+    assertions = map (acct: {
-      assertion = (acct.hashedPassword != null || acct.hashedPasswordFile != null);
+      assertion = acct.hashedPassword != null || acct.hashedPasswordFile != null;
       message = "${acct.name} must provide either a hashed password or a password hash file";
-    }) (lib.attrValues loginAccounts));
+    }) (lib.attrValues loginAccounts);
 
     # warn for accounts that specify both password and file
-    warnings = (map
+    warnings =
-      (acct: "${acct.name} specifies both a password hash and hash file; hash file will be used")
+      map (acct: "${acct.name} specifies both a password hash and hash file; hash file will be used")
-      (lib.filter
+        (
-        (acct: (acct.hashedPassword != null && acct.hashedPasswordFile != null))
+          lib.filter (acct: (acct.hashedPassword != null && acct.hashedPasswordFile != null)) (
-        (lib.attrValues loginAccounts)));
+            lib.attrValues loginAccounts
+          )
+        );
 
     # set the vmail gid to a specific value
     users.groups = {
-      "${vmailGroupName}" = { gid = vmailUID; };
+      "${vmailGroupName}" = {
+        gid = vmailUID;
+      };
     };
 
     # define all users
@@ -94,7 +117,7 @@ in {
 
     systemd.services.activate-virtual-mail-users = {
       wantedBy = [ "multi-user.target" ];
-      before = [ "dovecot2.service" ];
+      before = [ "dovecot.service" ];
       serviceConfig = {
         ExecStart = virtualMailUsersActivationScript;
       };

migrations/nixos-mailserver-migration-03.py

@@ -0,0 +1,146 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i python3 -p python3
+
+import argparse
+import os
+import shutil
+import sys
+from enum import Enum
+from pathlib import Path
+from pwd import getpwnam
+
+
+class FolderLayout(Enum):
+    Default = 1
+    Folder = 2
+
+
+def check_user(vmail_root: Path):
+    owner = vmail_root.owner()
+    owner_uid = getpwnam(owner).pw_uid
+
+    if os.geteuid() == owner_uid:
+        return
+
+    try:
+        print(
+            f"Trying to switch effective user id to {owner_uid} ({owner})",
+            file=sys.stderr,
+        )
+        os.seteuid(owner_uid)
+        return
+    except PermissionError:
+        print(
+            f"Failed switching to virtual mail user. Please run this script under it, for example by using `sudo -u {owner}`)",
+            file=sys.stderr,
+        )
+    sys.exit(1)
+
+
+def is_maildir_related(path: Path, layout: FolderLayout) -> bool:
+    if path.name in [
+        "subscriptions",
+        # https://doc.dovecot.org/2.3/admin_manual/mailbox_formats/maildir/#imap-uid-mapping
+        "dovecot-uidlist",
+        # https://doc.dovecot.org/2.3/admin_manual/mailbox_formats/maildir/#imap-keywords
+        "dovecot-keywords",
+    ]:
+        return True
+    if not path.is_dir():
+        return False
+    if path.name in ["cur", "new", "tmp"]:
+        return True
+    if layout is FolderLayout.Default and path.name.startswith("."):
+        return True
+    if layout is FolderLayout.Folder:
+        if path.name in ["mail"]:
+            return False
+        return True
+
+    return False
+
+
+def mkdir(dst: Path, dry_run: bool = True):
+    print(f'mkdir "{dst}"')
+    if not dry_run:
+        # u+rwx, setgid
+        dst.mkdir(mode=0o2700)
+
+
+def move(src: Path, dst: Path, dry_run: bool = True):
+    print(f'mv "{src}" "{dst}"')
+    if not dry_run:
+        src.rename(dst)
+
+
+def delete(dst: Path, dry_run: bool = True):
+    if not dst.exists():
+        return
+
+    if dst.is_dir():
+        print(f'rm --recursive "{dst}"')
+        if not dry_run:
+            shutil.rmtree(dst)
+    else:
+        print(f'rm "{dst}"')
+        if not dry_run:
+            dst.unlink()
+
+
+def main(vmail_root: Path, layout: FolderLayout, dry_run: bool = True):
+    maildirs = {path.parent for path in vmail_root.glob("*/*/cur")}
+    maybe_delete = []
+
+    # The old maildir will be the new home directory
+    for homedir in maildirs:
+        maildir = homedir / "mail"
+        mkdir(maildir, dry_run)
+
+        for path in homedir.iterdir():
+            if is_maildir_related(path, layout):
+                move(path, maildir / path.name, dry_run)
+            else:
+                maybe_delete.append(path)
+
+    # Files that are part of the previous home directory, but now obsolete
+    for path in [
+        vmail_root / ".dovecot.lda-dupes",
+        vmail_root / ".dovecot.lda-dupes.locks",
+    ]:
+        delete(path, dry_run)
+
+    # The remaining files are likely obsolete, but should still be checked with care
+    for path in maybe_delete:
+        print(f"# rm {str(path)}")
+
+    if dry_run:
+        print("\nNo changes were made.")
+        print("Run the script with `--execute` to apply the listed changes.")
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description="""
+        NixOS Mailserver Migration #3: Dovecot mail directory migration
+        (https://nixos-mailserver.readthedocs.io/en/latest/migrations.html#dovecot-mail-directory-migration)
+    """
+    )
+    parser.add_argument(
+        "vmail_root", type=Path, help="Path to the `mailserver.mailDirectory`"
+    )
+    parser.add_argument(
+        "--layout",
+        choices=["default", "folder"],
+        required=True,
+        help="Folder layout: 'default' unless `mailserver.useFsLayout` was enabled, then'folder'",
+    )
+    parser.add_argument(
+        "--execute", action="store_true", help="Actually perform changes"
+    )
+
+    args = parser.parse_args()
+
+    layout = FolderLayout.Default if args.layout == "default" else FolderLayout.Folder
+
+    check_user(args.vmail_root)
+    main(args.vmail_root, layout, not args.execute)

nixops/single-server.nix

@@ -1,31 +0,0 @@
-{
-  network.description = "mail server";
-
-  mailserver =
-    { config, pkgs, ... }:
-    {
-        imports = [
-            ../default.nix
-        ];
-
-        mailserver = {
-          enable = true;
-          fqdn = "mail.example.com";
-          domains = [ "example.com" "example2.com" ];
-          loginAccounts = {
-              "user1@example.com" = {
-                  hashedPassword = "$6$/z4n8AQl6K$kiOkBTWlZfBd7PvF5GsJ8PmPgdZsFGN1jPGZufxxr60PoR0oUsrvzm2oQiflyz5ir9fFJ.d/zKm/NgLXNUsNX/";
-              };
-          };
-          extraVirtualAliases = {
-              "info@example.com" = "user1@example.com";
-              "postmaster@example.com" = "user1@example.com";
-              "abuse@example.com" = "user1@example.com";
-              "user1@example2.com" = "user1@example.com";
-              "info@example2.com" = "user1@example.com";
-              "postmaster@example2.com" = "user1@example.com";
-              "abuse@example2.com" = "user1@example.com";
-          };
-        };
-    };
-}

nixops/vbox.nix

@@ -1,9 +0,0 @@
-{
-  mailserver =
-    { config, pkgs, ... }:
-    { deployment.targetEnv = "virtualbox";
-      deployment.virtualbox.memorySize = 1024; # megabytes
-      deployment.virtualbox.vcpu = 2; # number of cpus
-      deployment.virtualbox.headless = true;
-    };
-}

pyproject.toml

@@ -0,0 +1,5 @@
+[tool.ruff.lint]
+extend-select = ["ISC"]
+
+[tool.ruff.lint.flake8-implicit-str-concat]
+allow-multiline = false

scripts/generate-options.py

@@ -1,5 +1,7 @@
 import json
 import sys
+from textwrap import indent
+from typing import Any, Mapping
 
 header = """
 # Mailserver options
@@ -21,62 +23,90 @@ template = """
 f = open(sys.argv[1])
 options = json.load(f)
 
-groups = ["mailserver.loginAccounts",
+groups = [
+    "mailserver.loginAccounts",
     "mailserver.certificate",
     "mailserver.dkim",
+    "mailserver.srs",
     "mailserver.dmarcReporting",
     "mailserver.fullTextSearch",
     "mailserver.redis",
     "mailserver.ldap",
     "mailserver.monitoring",
     "mailserver.backup",
-          "mailserver.borgbackup"]
+    "mailserver.borgbackup",
+]
 
-def render_option_value(opt, attr):
-  if attr in opt:
-      if isinstance(opt[attr], dict) and '_type' in opt[attr]:
-          if opt[attr]['_type'] == 'literalExpression':
-              if '\n' in opt[attr]['text']:
-                  res = '\n```nix\n' + opt[attr]['text'].rstrip('\n') + '\n```'
-              else:
-                  res = '```{}```'.format(opt[attr]['text'])
-          elif opt[attr]['_type'] == 'literalMD':
-              res = opt[attr]['text']
-      else:
-          s = str(opt[attr])
-          if s == "":
-              res = '`""`'
-          elif '\n' in s:
-              res = '\n```\n' + s.rstrip('\n') + '\n```'
-          else:
-              res = '```{}```'.format(s)
-      res = '- ' + attr + ': ' + res
-  else:
-      res = ""
-  return res
 
-def print_option(opt):
+def md_literal(value: str) -> str:
-    if isinstance(opt['description'], dict) and '_type' in opt['description']: # mdDoc
+    return f"`{value}`"
-        description = opt['description']['text']
+
+
+def md_codefence(value: str, language: str = "nix") -> str:
+    return indent(
+        f"\n```{language}\n{value}\n```",
+        prefix=2 * " ",
+    )
+
+
+def render_option_value(option: Mapping[str, Any], key: str) -> str:
+    if key not in option:
+        return ""
+
+    if isinstance(option[key], dict) and "_type" in option[key]:
+        if option[key]["_type"] == "literalExpression":
+            # multi-line codeblock
+            if "\n" in option[key]["text"]:
+                text = option[key]["text"].rstrip("\n")
+                value = md_codefence(text)
+            # inline codeblock
             else:
-        description = opt['description']
+                value = md_literal(option[key]["text"])
-    print(template.format(
+        # literal markdown
-        key=opt['name'],
+        elif option[key]["_type"] == "literalMD":
+            value = option[key]["text"]
+        else:
+            assert RuntimeError(f"Unhandled option type {option[key]['_type']}")
+    else:
+        text = str(option[key])
+        if text == "":
+            value = md_literal('""')
+        elif "\n" in text:
+            value = md_codefence(text.rstrip("\n"))
+        else:
+            value = md_literal(text)
+
+    return f"- {key}: {value}"  # type: ignore
+
+
+def print_option(option):
+    if (
+        isinstance(option["description"], dict) and "_type" in option["description"]
+    ):  # mdDoc
+        description = option["description"]["text"]
+    else:
+        description = option["description"]
+    print(
+        template.format(
+            key=option["name"],
             description=description or "",
-        type="- type: ```{}```".format(opt['type']),
+            type=f"- type: {md_literal(option['type'])}",
-        default=render_option_value(opt, 'default'),
+            default=render_option_value(option, "defaultText")
-        example=render_option_value(opt, 'example')))
+            if "defaultText" in option
+            else render_option_value(option, "default"),
+            example=render_option_value(option, "example"),
+        )
+    )
 
 
 print(header)
 for opt in options:
-    if any([opt['name'].startswith(c) for c in groups]):
+    if any([opt["name"].startswith(c) for c in groups]):
         continue
     print_option(opt)
 
 for c in groups:
-    print('## `{}`'.format(c))
+    print(f"## `{c}`\n")
-    print()
     for opt in options:
-        if opt['name'].startswith(c):
+        if opt["name"].startswith(c):
             print_option(opt)

scripts/mail-check.py

@@ -1,31 +1,45 @@
-import smtplib, sys
 import argparse
-import os
-import uuid
-import imaplib
-from datetime import datetime, timedelta
 import email
+import email.utils
+import imaplib
+import smtplib
 import time
+import uuid
+from datetime import datetime, timedelta
+from typing import cast
 
 RETRY = 100
 
-def _send_mail(smtp_host, smtp_port, smtp_username, from_addr, from_pwd, to_addr, subject, starttls):
-    print("Sending mail with subject '{}'".format(subject))
-    message = "\n".join([
-        "From: {from_addr}",
-        "To: {to_addr}",
-        "Subject: {subject}",
-        "",
-        "This validates our mail server can send to Gmail :/"]).format(
-            from_addr=from_addr,
-            to_addr=to_addr,
-            subject=subject)
 
+def _send_mail(
+    smtp_host,
+    smtp_port,
+    smtp_username,
+    from_addr,
+    from_pwd,
+    to_addr,
+    subject,
+    starttls,
+    ssl,
+):
+    print(f"Sending mail with subject '{subject}'")
+    message = "\n".join(
+        [
+            f"From: {from_addr}",
+            f"To: {to_addr}",
+            f"Subject: {subject}",
+            f"Message-ID: {uuid.uuid4()}@mail-check.py",
+            f"Date: {email.utils.formatdate()}",
+            "",
+            "This validates our mail server can send to Gmail :/",
+        ]
+    )
 
     retry = RETRY
+    smtp_class = smtplib.SMTP_SSL if ssl else smtplib.SMTP
     while True:
         try:
-            with smtplib.SMTP(smtp_host, port=smtp_port) as smtp:
+            with smtp_class(smtp_host, port=smtp_port) as smtp:
                 try:
                     if starttls:
                         smtp.starttls()
@@ -37,7 +51,9 @@ def _send_mail(smtp_host, smtp_port, smtp_username, from_addr, from_pwd, to_addr
                 except smtplib.SMTPResponseException as e:
                     if e.smtp_code == 451:  # service unavailable error
                         print(e)
-                    elif e.smtp_code == 454:  # smtplib.SMTPResponseException: (454, b'4.3.0 Try again later')
+                    elif (
+                        e.smtp_code == 454
+                    ):  # smtplib.SMTPResponseException: (454, b'4.3.0 Try again later')
                         print(e)
                     else:
                         raise
@@ -55,6 +71,7 @@ def _send_mail(smtp_host, smtp_port, smtp_username, from_addr, from_pwd, to_addr
             print("Retry attempts exhausted")
             exit(5)
 
+
 def _read_mail(
     imap_host,
     imap_port,
@@ -63,8 +80,9 @@ def _read_mail(
     subject,
     ignore_dkim_spf,
     show_body=False,
-        delete=True):
+    delete=True,
-    print("Reading mail from %s" % imap_username)
+):
+    print(f"Reading mail from {imap_username}")
 
     message = None
 
@@ -74,49 +92,62 @@ def _read_mail(
 
     today = datetime.today()
     cutoff = today - timedelta(days=1)
-    dt = cutoff.strftime('%d-%b-%Y')
+    dt = cutoff.strftime("%d-%b-%Y")
     for _ in range(0, RETRY):
         print("Retrying")
         obj.select()
-        typ, data = obj.search(None, '(SINCE %s) (SUBJECT "%s")'%(dt, subject))
+        _, data = obj.search(None, f'(SINCE {dt}) (SUBJECT "{subject}")')
-        if data == [b'']:
+        if data == [b""]:
             time.sleep(1)
             continue
 
         uids = data[0].decode("utf-8").split(" ")
         if len(uids) != 1:
-          print("Warning: %d messages have been found with subject containing %s " % (len(uids), subject))
+            print(
+                f"Warning: {len(uids)} messages have been found with subject containing {subject}"
+            )
 
         # FIXME: we only consider the first matching message...
         uid = uids[0]
-        _, raw = obj.fetch(uid, '(RFC822)')
+        _, raw = obj.fetch(uid, "(RFC822)")
         if delete:
-            obj.store(uid, '+FLAGS', '\\Deleted')
+            obj.store(uid, "+FLAGS", "\\Deleted")
             obj.expunge()
-        message = email.message_from_bytes(raw[0][1])
+        assert raw[0] and raw[0][1]
-        print("Message with subject '%s' has been found" % message['subject'])
+        message = email.message_from_bytes(cast(bytes, raw[0][1]))
+        print(f"Message with subject '{message['subject']}' has been found")
         if show_body:
-            for m in message.get_payload():
+            if message.is_multipart():
-                if m.get_content_type() == 'text/plain':
+                for part in message.walk():
-                    print("Body:\n%s" % m.get_payload(decode=True).decode('utf-8'))
+                    ctype = part.get_content_type()
+                    if ctype == "text/plain":
+                        body = cast(bytes, part.get_payload(decode=True)).decode()
+                        print(f"Body:\n{body}")
+                    else:
+                        print(f"Body with content type {ctype} not printed")
+            else:
+                body = cast(bytes, message.get_payload(decode=True)).decode()
+                print(f"Body:\n{body}")
         break
 
     if message is None:
-        print("Error: no message with subject '%s' has been found in INBOX of %s" % (subject, imap_username))
+        print(
+            f"Error: no message with subject '{subject}' has been found in INBOX of {imap_username}"
+        )
         exit(1)
 
     if ignore_dkim_spf:
         return
 
     # gmail set this standardized header
-    if 'ARC-Authentication-Results' in message:
+    if "ARC-Authentication-Results" in message:
-        if "dkim=pass" in message['ARC-Authentication-Results']:
+        if "dkim=pass" in message["ARC-Authentication-Results"]:
             print("DKIM ok")
         else:
             print("Error: no DKIM validation found in message:")
             print(message.as_string())
             exit(2)
-        if "spf=pass" in message['ARC-Authentication-Results']:
+        if "spf=pass" in message["ARC-Authentication-Results"]:
             print("SPF ok")
         else:
             print("Error: no SPF validation found in message:")
@@ -126,71 +157,110 @@ def _read_mail(
         print("DKIM and SPF verification failed")
         exit(4)
 
+
 def send_and_read(args):
     src_pwd = None
     if args.src_password_file is not None:
         src_pwd = args.src_password_file.readline().rstrip()
     dst_pwd = args.dst_password_file.readline().rstrip()
 
-    if args.imap_username != '':
+    if args.imap_username != "":
         imap_username = args.imap_username
     else:
         imap_username = args.to_addr
 
-    subject = "{}".format(uuid.uuid4())
+    subject = f"{uuid.uuid4()}"
 
-    _send_mail(smtp_host=args.smtp_host,
+    _send_mail(
+        smtp_host=args.smtp_host,
         smtp_port=args.smtp_port,
         smtp_username=args.smtp_username,
         from_addr=args.from_addr,
         from_pwd=src_pwd,
         to_addr=args.to_addr,
         subject=subject,
-               starttls=args.smtp_starttls)
+        starttls=args.smtp_starttls,
+        ssl=args.smtp_ssl,
+    )
 
-    _read_mail(imap_host=args.imap_host,
+    _read_mail(
+        imap_host=args.imap_host,
         imap_port=args.imap_port,
         imap_username=imap_username,
         to_pwd=dst_pwd,
         subject=subject,
-               ignore_dkim_spf=args.ignore_dkim_spf)
+        ignore_dkim_spf=args.ignore_dkim_spf,
+    )
+
 
 def read(args):
-    _read_mail(imap_host=args.imap_host,
+    _read_mail(
+        imap_host=args.imap_host,
         imap_port=args.imap_port,
-               to_addr=args.imap_username,
+        imap_username=args.imap_username,
         to_pwd=args.imap_password,
         subject=args.subject,
         ignore_dkim_spf=args.ignore_dkim_spf,
         show_body=args.show_body,
-               delete=False)
+        delete=False,
+    )
+
 
 parser = argparse.ArgumentParser()
 subparsers = parser.add_subparsers()
 
-parser_send_and_read = subparsers.add_parser('send-and-read', description="Send a email with a subject containing a random UUID and then try to read this email from the recipient INBOX.")
+parser_send_and_read = subparsers.add_parser(
-parser_send_and_read.add_argument('--smtp-host', type=str)
+    "send-and-read",
-parser_send_and_read.add_argument('--smtp-port', type=str, default=25)
+    description="Send a email with a subject containing a random UUID and then try to read this email from the recipient INBOX.",
-parser_send_and_read.add_argument('--smtp-starttls', action='store_true')
+)
-parser_send_and_read.add_argument('--smtp-username', type=str, default='', help="username used for smtp login. If not specified, the from-addr value is used")
+parser_send_and_read.add_argument("--smtp-host", type=str)
-parser_send_and_read.add_argument('--from-addr', type=str)
+parser_send_and_read.add_argument("--smtp-port", type=str, default=25)
-parser_send_and_read.add_argument('--imap-host', required=True, type=str)
+parser_send_and_read.add_argument("--smtp-starttls", action="store_true")
-parser_send_and_read.add_argument('--imap-port', type=str, default=993)
+parser_send_and_read.add_argument("--smtp-ssl", action="store_true")
-parser_send_and_read.add_argument('--to-addr', type=str, required=True)
+parser_send_and_read.add_argument(
-parser_send_and_read.add_argument('--imap-username', type=str, default='', help="username used for imap login. If not specified, the to-addr value is used")
+    "--smtp-username",
-parser_send_and_read.add_argument('--src-password-file', type=argparse.FileType('r'))
+    type=str,
-parser_send_and_read.add_argument('--dst-password-file', required=True, type=argparse.FileType('r'))
+    default="",
-parser_send_and_read.add_argument('--ignore-dkim-spf', action='store_true', help="to ignore the dkim and spf verification on the read mail")
+    help="username used for smtp login. If not specified, the from-addr value is used",
+)
+parser_send_and_read.add_argument("--from-addr", type=str)
+parser_send_and_read.add_argument("--imap-host", required=True, type=str)
+parser_send_and_read.add_argument("--imap-port", type=str, default=993)
+parser_send_and_read.add_argument("--to-addr", type=str, required=True)
+parser_send_and_read.add_argument(
+    "--imap-username",
+    type=str,
+    default="",
+    help="username used for imap login. If not specified, the to-addr value is used",
+)
+parser_send_and_read.add_argument("--src-password-file", type=argparse.FileType("r"))
+parser_send_and_read.add_argument(
+    "--dst-password-file", required=True, type=argparse.FileType("r")
+)
+parser_send_and_read.add_argument(
+    "--ignore-dkim-spf",
+    action="store_true",
+    help="to ignore the dkim and spf verification on the read mail",
+)
 parser_send_and_read.set_defaults(func=send_and_read)
 
-parser_read = subparsers.add_parser('read', description="Search for an email with a subject containing 'subject' in the INBOX.")
+parser_read = subparsers.add_parser(
-parser_read.add_argument('--imap-host', type=str, default="localhost")
+    "read",
-parser_read.add_argument('--imap-port', type=str, default=993)
+    description="Search for an email with a subject containing 'subject' in the INBOX.",
-parser_read.add_argument('--imap-username', required=True, type=str)
+)
-parser_read.add_argument('--imap-password', required=True, type=str)
+parser_read.add_argument("--imap-host", type=str, default="localhost")
-parser_read.add_argument('--ignore-dkim-spf', action='store_true', help="to ignore the dkim and spf verification on the read mail")
+parser_read.add_argument("--imap-port", type=str, default=993)
-parser_read.add_argument('--show-body', action='store_true', help="print mail text/plain payload")
+parser_read.add_argument("--imap-username", required=True, type=str)
-parser_read.add_argument('subject', type=str)
+parser_read.add_argument("--imap-password", required=True, type=str)
+parser_read.add_argument(
+    "--ignore-dkim-spf",
+    action="store_true",
+    help="to ignore the dkim and spf verification on the read mail",
+)
+parser_read.add_argument(
+    "--show-body", action="store_true", help="print mail text/plain payload"
+)
+parser_read.add_argument("subject", type=str)
 parser_read.set_defaults(func=read)
 
 args = parser.parse_args()

shell.nix

@@ -1,10 +1,9 @@
-(import
+(import (
-  (
+  let
-    let lock = builtins.fromJSON (builtins.readFile ./flake.lock); in
+    lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+  in
   fetchTarball {
     url = "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
     sha256 = lock.nodes.flake-compat.locked.narHash;
   }
-  )
+) { src = ./.; }).shellNix
-  { src = ./.; }
-).shellNix

tests/clamav.nix

@@ -14,12 +14,18 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ pkgs ? import <nixpkgs> {}, blobs}:
+{
+  lib,
+  blobs,
+  ...
+}:
 
-pkgs.nixosTest {
+{
   name = "clamav";
+
   nodes = {
-    server = { config, pkgs, lib, ... }:
+    server =
+      { pkgs, ... }:
       {
         imports = [
           ../default.nix
@@ -28,6 +34,8 @@ pkgs.nixosTest {
 
         virtualisation.memorySize = 1500;
 
+        environment.systemPackages = with pkgs; [ netcat ];
+
         services.rsyslogd = {
           enable = true;
           defaultConfig = ''
@@ -63,7 +71,10 @@ pkgs.nixosTest {
         mailserver = {
           enable = true;
           fqdn = "mail.example.com";
-              domains = [ "example.com" "example2.com" ];
+          domains = [
+            "example.com"
+            "example2.com"
+          ];
           virusScanning = true;
 
           loginAccounts = {
@@ -83,21 +94,28 @@ pkgs.nixosTest {
           "root/eicar.com.txt".text = "X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*";
         };
       };
-      client = { nodes, config, pkgs, ... }: let
+    client =
-        serverIP = nodes.server.config.networking.primaryIPAddress;
+      { nodes, pkgs, ... }:
-        clientIP = nodes.client.config.networking.primaryIPAddress;
+      let
+        serverIP = nodes.server.networking.primaryIPAddress;
+        clientIP = nodes.client.networking.primaryIPAddress;
         grep-ip = pkgs.writeScriptBin "grep-ip" ''
           #!${pkgs.stdenv.shell}
           echo grep '${clientIP}' "$@" >&2
           exec grep '${clientIP}' "$@"
         '';
-      in {
+      in
+      {
         imports = [
           ./lib/config.nix
         ];
 
         environment.systemPackages = with pkgs; [
-          fetchmail msmtp procmail findutils grep-ip
+          fetchmail
+          msmtp
+          procmail
+          findutils
+          grep-ip
         ];
         environment.etc = {
           "root/.fetchmailrc" = {
@@ -180,8 +198,7 @@ pkgs.nixosTest {
       };
   };
 
-  testScript = { nodes, ... }:
+  testScript = ''
-      ''
     start_all()
 
     server.wait_for_unit("multi-user.target")
@@ -189,10 +206,10 @@ pkgs.nixosTest {
 
     # TODO put this blocking into the systemd units? I am not sure if rspamd already waits for the clamd socket.
     server.wait_until_succeeds(
-          "set +e; timeout 1 ${nodes.server.nixpkgs.pkgs.netcat}/bin/nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
+        "set +e; timeout 1 nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
     )
     server.wait_until_succeeds(
-          "set +e; timeout 1 ${nodes.server.nixpkgs.pkgs.netcat}/bin/nc -U /run/clamav/clamd.ctl < /dev/null; [ $? -eq 124 ]"
+        "set +e; timeout 1 nc -U /run/clamav/clamd.ctl < /dev/null; [ $? -eq 124 ]"
     )
 
     client.execute("cp -p /etc/root/.* ~/")
@@ -222,7 +239,7 @@ pkgs.nixosTest {
 
     with subtest("virus scan email"):
         client.succeed(
-              'set +o pipefail; msmtp -a user2 user1\@example.com < /etc/root/virus-email 2>&1 | tee /dev/stderr | grep "server message: 554 5\\.7\\.1" >&2'
+            'set +o pipefail; msmtp -a user2 user1@example.com < /etc/root/virus-email 2>&1 | tee /dev/stderr | grep "server message: 554 5\\.7\\.1" >&2'
         )
         server.succeed("journalctl -u rspamd | grep -i eicar")
         # give the mail server some time to process the mail

tests/external.nix

@@ -14,18 +14,20 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ pkgs ? import <nixpkgs> {}, ...}:
+{
-
-pkgs.nixosTest {
   name = "external";
+
   nodes = {
-    server = { config, pkgs, ... }:
+    server =
+      { pkgs, ... }:
       {
         imports = [
           ../default.nix
           ./lib/config.nix
         ];
 
+        environment.systemPackages = with pkgs; [ netcat ];
+
         virtualisation.memorySize = 1024;
 
         services.rsyslogd = {
@@ -35,19 +37,17 @@ pkgs.nixosTest {
           '';
         };
 
-
         mailserver = {
           enable = true;
-              debug = true;
+          debug.dovecot = true; # enabled for sieve script logging
           fqdn = "mail.example.com";
-              domains = [ "example.com" "example2.com" ];
+          domains = [
+            "example.com"
+            "example2.com"
+          ];
           rewriteMessageId = true;
           dkimKeyBits = 1535;
-              dmarcReporting = {
+          dmarcReporting.enable = true;
-                enable = true;
-                domain = "example.com";
-                organizationName = "ACME Corp";
-              };
 
           loginAccounts = {
             "user1@example.com" = {
@@ -70,7 +70,10 @@ pkgs.nixosTest {
 
           extraVirtualAliases = {
             "single-alias@example.com" = "user1@example.com";
-                "multi-alias@example.com" = [ "user1@example.com" "user2@example.com" ];
+            "multi-alias@example.com" = [
+              "user1@example.com"
+              "user2@example.com"
+            ];
           };
 
           enableImap = true;
@@ -79,16 +82,18 @@ pkgs.nixosTest {
             enable = true;
             autoIndex = true;
             # special use depends on https://github.com/NixOS/nixpkgs/pull/93201
-                autoIndexExclude = [ (if (pkgs.lib.versionAtLeast pkgs.lib.version "21") then "\\Junk" else "Junk") ];
+            autoIndexExclude = [
+              (if (pkgs.lib.versionAtLeast pkgs.lib.version "21") then "\\Junk" else "Junk")
+            ];
             enforced = "yes";
-                # fts-xapian warns when memory is low, which makes the test fail
-                memoryLimit = 100000;
           };
         };
       };
-      client = { nodes, config, pkgs, ... }: let
+    client =
-        serverIP = nodes.server.config.networking.primaryIPAddress;
+      { nodes, pkgs, ... }:
-        clientIP = nodes.client.config.networking.primaryIPAddress;
+      let
+        serverIP = nodes.server.networking.primaryIPAddress;
+        clientIP = nodes.client.networking.primaryIPAddress;
         grep-ip = pkgs.writeScriptBin "grep-ip" ''
           #!${pkgs.stdenv.shell}
           echo grep '${clientIP}' "$@" >&2
@@ -173,12 +178,21 @@ pkgs.nixosTest {
             assert needle in repr(response)
             imap.close()
         '';
-      in {
+      in
+      {
         imports = [
           ./lib/config.nix
         ];
         environment.systemPackages = with pkgs; [
-          fetchmail msmtp procmail findutils grep-ip check-mail-id test-imap-spam test-imap-ham search
+          fetchmail
+          msmtp
+          procmail
+          findutils
+          grep-ip
+          check-mail-id
+          test-imap-spam
+          test-imap-ham
+          search
         ];
         environment.etc = {
           "root/.fetchmailrc" = {
@@ -272,7 +286,7 @@ pkgs.nixosTest {
             To: Chuck <chuck@example.com>
             Cc:
             Bcc:
-            Subject: This is a test Email from postmaster\@example.com to chuck
+            Subject: This is a test Email from postmaster@example.com to chuck
             Reply-To:
 
             Hello Chuck,
@@ -286,7 +300,7 @@ pkgs.nixosTest {
             To: User1 <user1@example.com>
             Cc:
             Bcc:
-            Subject: This is a test Email from single-alias\@example.com to user1
+            Subject: This is a test Email from single-alias@example.com to user1
             Reply-To:
 
             Hello User1,
@@ -301,7 +315,7 @@ pkgs.nixosTest {
             To: Multi Alias <multi-alias@example.com>
             Cc:
             Bcc:
-            Subject: This is a test Email from user2\@example.com to multi-alias
+            Subject: This is a test Email from user2@example.com to multi-alias
             Reply-To:
 
             Hello Multi Alias,
@@ -341,8 +355,7 @@ pkgs.nixosTest {
       };
   };
 
-  testScript = { nodes, ... }:
+  testScript = ''
-      ''
     start_all()
 
     server.wait_for_unit("multi-user.target")
@@ -350,7 +363,7 @@ pkgs.nixosTest {
 
     # TODO put this blocking into the systemd units?
     server.wait_until_succeeds(
-          "set +e; timeout 1 ${nodes.server.nixpkgs.pkgs.netcat}/bin/nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
+        "set +e; timeout 1 nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
     )
 
     client.execute("cp -p /etc/root/.* ~/")
@@ -367,7 +380,7 @@ pkgs.nixosTest {
     with subtest("submission port send mail"):
         # send email from user2 to user1
         client.succeed(
-              "msmtp -a test --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email1 >&2"
+            "msmtp -a test --tls=on --tls-certcheck=off --auth=on user1@example.com < /etc/root/email1 >&2"
         )
         # give the mail server some time to process the mail
         server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
@@ -395,20 +408,20 @@ pkgs.nixosTest {
         client.execute("rm ~/mail/*")
         # send email from user2 to user1
         client.succeed(
-              "msmtp -a test2 --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email2 >&2"
+            "msmtp -a test2 --tls=on --tls-certcheck=off --auth=on user1@example.com < /etc/root/email2 >&2"
         )
         server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
         # fetchmail returns EXIT_CODE 0 when it retrieves mail
         client.succeed("fetchmail  --nosslcertck -v")
         client.succeed("cat ~/mail/* >&2")
         # make sure it is dkim signed
-          client.succeed("grep DKIM ~/mail/*")
+        client.succeed("grep DKIM-Signature: ~/mail/*")
 
     with subtest("aliases"):
         client.execute("rm ~/mail/*")
         # send email from chuck to postmaster
         client.succeed(
-              "msmtp -a test3 --tls=on --tls-certcheck=off --auth=on postmaster\@example.com < /etc/root/email2 >&2"
+            "msmtp -a test3 --tls=on --tls-certcheck=off --auth=on postmaster@example.com < /etc/root/email2 >&2"
         )
         server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
         # fetchmail returns EXIT_CODE 0 when it retrieves mail
@@ -418,7 +431,7 @@ pkgs.nixosTest {
         client.execute("rm ~/mail/*")
         # send email from chuck to non exsitent account
         client.succeed(
-              "msmtp -a test3 --tls=on --tls-certcheck=off --auth=on lol\@example.com < /etc/root/email2 >&2"
+            "msmtp -a test3 --tls=on --tls-certcheck=off --auth=on lol@example.com < /etc/root/email2 >&2"
         )
         server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
         # fetchmail returns EXIT_CODE 0 when it retrieves mail
@@ -427,7 +440,7 @@ pkgs.nixosTest {
         client.execute("rm ~/mail/*")
         # send email from user1 to chuck
         client.succeed(
-              "msmtp -a test4 --tls=on --tls-certcheck=off --auth=on chuck\@example.com < /etc/root/email2 >&2"
+            "msmtp -a test4 --tls=on --tls-certcheck=off --auth=on chuck@example.com < /etc/root/email2 >&2"
         )
         server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
         # fetchmail returns EXIT_CODE 1 when no new mail
@@ -438,7 +451,7 @@ pkgs.nixosTest {
         client.execute("rm ~/mail/*")
         # send email from single-alias to user1
         client.succeed(
-              "msmtp -a test5 --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email4 >&2"
+            "msmtp -a test5 --tls=on --tls-certcheck=off --auth=on user1@example.com < /etc/root/email4 >&2"
         )
         server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
         # fetchmail returns EXIT_CODE 0 when it retrieves mail
@@ -447,7 +460,7 @@ pkgs.nixosTest {
         client.execute("rm ~/mail/*")
         # send email from user1 to multi-alias (user{1,2}@example.com)
         client.succeed(
-              "msmtp -a test --tls=on --tls-certcheck=off --auth=on multi-alias\@example.com < /etc/root/email5 >&2"
+            "msmtp -a test --tls=on --tls-certcheck=off --auth=on multi-alias@example.com < /etc/root/email5 >&2"
         )
         server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
         # fetchmail returns EXIT_CODE 0 when it retrieves mail
@@ -458,7 +471,7 @@ pkgs.nixosTest {
         client.execute("mv ~/.fetchmailRcLowQuota ~/.fetchmailrc")
 
         client.succeed(
-              "msmtp -a test3 --tls=on --tls-certcheck=off --auth=on lowquota\@example.com < /etc/root/email2 >&2"
+            "msmtp -a test3 --tls=on --tls-certcheck=off --auth=on lowquota@example.com < /etc/root/email2 >&2"
         )
         server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
         # fetchmail returns EXIT_CODE 0 when it retrieves mail
@@ -467,23 +480,23 @@ pkgs.nixosTest {
     with subtest("imap sieve junk trainer"):
         # send email from user2 to user1
         client.succeed(
-              "msmtp -a test --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email1 >&2"
+            "msmtp -a test --tls=on --tls-certcheck=off --auth=on user1@example.com < /etc/root/email1 >&2"
         )
         # give the mail server some time to process the mail
         server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
 
         client.succeed("imap-mark-spam >&2")
-          server.wait_until_succeeds("journalctl -u dovecot2 | grep -i sa-learn-spam.sh >&2")
+        server.wait_until_succeeds("journalctl -u dovecot -u dovecot2 | grep -i rspamd-learn-spam.sh >&2")
         client.succeed("imap-mark-ham >&2")
-          server.wait_until_succeeds("journalctl -u dovecot2 | grep -i sa-learn-ham.sh >&2")
+        server.wait_until_succeeds("journalctl -u dovecot -u dovecot2 | grep -i rspamd-learn-ham.sh >&2")
 
     with subtest("full text search and indexation"):
         # send 2 email from user2 to user1
         client.succeed(
-              "msmtp -a test --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email6 >&2"
+            "msmtp -a test --tls=on --tls-certcheck=off --auth=on user1@example.com < /etc/root/email6 >&2"
         )
         client.succeed(
-              "msmtp -a test --tls=on --tls-certcheck=off --auth=on user1\@example.com < /etc/root/email7 >&2"
+            "msmtp -a test --tls=on --tls-certcheck=off --auth=on user1@example.com < /etc/root/email7 >&2"
         )
         # give the mail server some time to process the mail
         server.wait_until_fails('[ "$(postqueue -p)" != "Mail queue is empty" ]')
@@ -493,23 +506,23 @@ pkgs.nixosTest {
         # should fail because this folder is not indexed
         client.fail("search Junk a >&2")
         # check that search really goes through the indexer
-          server.succeed(
+        server.succeed("journalctl -u dovecot -u dovecot2 | grep 'fts-flatcurve(INBOX): Query ' >&2")
-              "journalctl -u dovecot2 | grep -E 'indexer-worker.* Done indexing .INBOX.' >&2"
-          )
         # check that Junk is not indexed
-          server.fail("journalctl -u dovecot2 | grep 'indexer-worker' | grep -i 'JUNK' >&2")
+        server.fail("journalctl -u dovecot -u dovecot2 | grep 'fts-flatcurve(JUNK): Indexing ' >&2")
 
     with subtest("dmarc reporting"):
         server.systemctl("start rspamd-dmarc-reporter.service")
-          server.wait_until_succeeds("journalctl -eu rspamd-dmarc-reporter.service -o cat | grep -q 'No reports for '")
 
     with subtest("no warnings or errors"):
         server.fail("journalctl -u postfix | grep -i error >&2")
         server.fail("journalctl -u postfix | grep -i warning >&2")
-          server.fail("journalctl -u dovecot2 | grep -i error >&2")
+        server.fail("journalctl -u dovecot -u dovecot2 | grep -v 'imap-login: Debug: SSL error: Connection closed' | grep -i error >&2")
         # harmless ? https://dovecot.org/pipermail/dovecot/2020-August/119575.html
         server.fail(
-              "journalctl -u dovecot2 |grep -v 'Expunged message reappeared, giving a new UID'| grep -i warning >&2"
+          "journalctl -u dovecot -u dovecot2 | \
+            grep -v 'Expunged message reappeared, giving a new UID' | \
+            grep -v 'Time moved forwards' | \
+            grep -i warning >&2"
         )
   '';
 }

tests/internal.nix

@@ -14,7 +14,10 @@
 #  You should have received a copy of the GNU General Public License
 #  along with this program. If not, see <http://www.gnu.org/licenses/>
 
-{ pkgs ? import <nixpkgs> {}, ...}:
+{
+  pkgs,
+  ...
+}:
 
 let
   sendMail = pkgs.writeTextFile {
@@ -27,19 +30,27 @@ let
     '';
   };
 
-  hashPassword = password: pkgs.runCommand
+  hashPassword =
-    "password-${password}-hashed"
+    password:
-    { buildInputs = [ pkgs.mkpasswd ]; inherit password; } ''
+    pkgs.runCommand "password-${password}-hashed"
+      {
+        buildInputs = [ pkgs.mkpasswd ];
+        inherit password;
+      }
+      ''
         mkpasswd -sm bcrypt <<<"$password" > $out
       '';
 
   hashedPasswordFile = hashPassword "my-password";
   passwordFile = pkgs.writeText "password" "my-password";
 in
-pkgs.nixosTest {
+{
   name = "internal";
+
   nodes = {
-    machine = { config, pkgs, ... }: {
+    machine =
+      { pkgs, ... }:
+      {
         imports = [
           ./../default.nix
           ./lib/config.nix
@@ -50,12 +61,21 @@ pkgs.nixosTest {
         environment.systemPackages = [
           (pkgs.writeScriptBin "mail-check" ''
             ${pkgs.python3}/bin/python ${../scripts/mail-check.py} $@
-        '')];
+          '')
+        ]
+        ++ (with pkgs; [
+          curl
+          openssl
+          netcat
+        ]);
 
         mailserver = {
           enable = true;
           fqdn = "mail.example.com";
-        domains = [ "example.com" "domain.com" ];
+          domains = [
+            "example.com"
+            "domain.com"
+          ];
           localDnsResolver = false;
 
           loginAccounts = {
@@ -79,18 +99,24 @@ pkgs.nixosTest {
 
           vmailGroupName = "vmail";
           vmailUID = 5000;
+          indexDir = "/var/lib/dovecot/indices";
 
           enableImap = false;
         };
       };
   };
-  testScript = ''
+  testScript =
+    {
+      nodes,
+      ...
+    }:
+    ''
       machine.start()
       machine.wait_for_unit("multi-user.target")
 
       # Regression test for https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/issues/205
       with subtest("mail forwarded can are locally kept"):
-        # A mail sent to user2@example.com is in the user1@example.com mailbox
+          # A mail sent to user2@example.com via explicit TLS is in the user1@example.com mailbox
           machine.succeed(
               " ".join(
                   [
@@ -108,13 +134,13 @@ pkgs.nixosTest {
                   ]
               )
           )
-        # A mail sent to user2@example.com is in the user2@example.com mailbox
+          # A mail sent to user2@example.com via implicit TLS is in the user2@example.com mailbox
           machine.succeed(
               " ".join(
                   [
                       "mail-check send-and-read",
-                    "--smtp-port 587",
+                      "--smtp-port 465",
-                    "--smtp-starttls",
+                      "--smtp-ssl",
                       "--smtp-host localhost",
                       "--imap-host localhost",
                       "--imap-username user2@example.com",
@@ -128,7 +154,7 @@ pkgs.nixosTest {
           )
 
       with subtest("regex email alias are received"):
-        # A mail sent to user2-regex-alias@domain.com is in the user2@example.com mailbox
+          # A mail sent to user2-regex-alias@domain.com via explicit TLS is in the user2@example.com mailbox
           machine.succeed(
               " ".join(
                   [
@@ -148,13 +174,14 @@ pkgs.nixosTest {
           )
 
       with subtest("user can send from regex email alias"):
-        # A mail sent from user2-regex-alias@domain.com, using user2@example.com credentials is received
+          # A mail sent to user1@example.com from user2-regex-alias@domain.com by
+          # user2@example.com via implicit TLS is in the user1@example.com mailbox
           machine.succeed(
               " ".join(
                   [
                       "mail-check send-and-read",
-                    "--smtp-port 587",
+                      "--smtp-port 465",
-                    "--smtp-starttls",
+                      "--smtp-ssl",
                       "--smtp-host localhost",
                       "--imap-host localhost",
                       "--smtp-username user2@example.com",
@@ -170,26 +197,31 @@ pkgs.nixosTest {
       with subtest("vmail gid is set correctly"):
           machine.succeed("getent group vmail | grep 5000")
 
+      with subtest("Check dovecot maildir and index locations"):
+          # If these paths change we need a migration
+          machine.succeed("doveadm user -f home user1@example.com | grep ${nodes.machine.mailserver.mailDirectory}/example.com/user1")
+          machine.succeed("doveadm user -f mail user1@example.com | grep 'maildir:~/mail:INDEX=${nodes.machine.mailserver.indexDir}/example.com/user1'")
+
       with subtest("mail to send only accounts is rejected"):
           machine.wait_for_open_port(25)
           # TODO put this blocking into the systemd units
           machine.wait_until_succeeds(
-            "set +e; timeout 1 ${pkgs.netcat}/bin/nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
+              "set +e; timeout 1 nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
           )
           machine.succeed(
-            "cat ${sendMail} | ${pkgs.netcat-gnu}/bin/nc localhost 25 | grep -q 'This account cannot receive emails'"
+              "cat ${sendMail} | nc localhost 25 | grep -q '554 5.5.0 Error'"
           )
 
       with subtest("rspamd controller serves web ui"):
           machine.succeed(
-            "set +o pipefail; ${pkgs.curl}/bin/curl --unix-socket /run/rspamd/worker-controller.sock http://localhost/ | grep -q '<body>'"
+              "set +o pipefail; curl --unix-socket /run/rspamd/worker-controller.sock http://localhost/ | grep -q '<body>'"
           )
 
       with subtest("imap port 143 is closed and imaps is serving SSL"):
           machine.wait_for_closed_port(143)
           machine.wait_for_open_port(993)
           machine.succeed(
-            "echo | ${pkgs.openssl}/bin/openssl s_client -connect localhost:993 | grep 'New, TLS'"
+              "echo | openssl s_client -connect localhost:993 | grep 'New, TLS'"
           )
     '';
 }

tests/ldap.nix

@@ -1,16 +1,15 @@
-{ pkgs ? import <nixpkgs> {}
-, ...
-}:
-
 let
   bindPassword = "unsafegibberish";
   alicePassword = "testalice";
   bobPassword = "testbob";
 in
-pkgs.nixosTest {
+{
   name = "ldap";
+
   nodes = {
-    machine = { config, pkgs, ... }: {
+    machine =
+      { pkgs, ... }:
+      {
         imports = [
           ./../default.nix
           ./lib/config.nix
@@ -20,13 +19,14 @@ pkgs.nixosTest {
 
         services.openssh = {
           enable = true;
-        permitRootLogin = "yes";
+          settings.PermitRootLogin = "yes";
         };
 
         environment.systemPackages = [
           (pkgs.writeScriptBin "mail-check" ''
             ${pkgs.python3}/bin/python ${../scripts/mail-check.py} $@
-        '')];
+          '')
+        ];
 
         environment.etc.bind-password.text = bindPassword;
 
@@ -90,6 +90,7 @@ pkgs.nixosTest {
           fqdn = "mail.example.com";
           domains = [ "example.com" ];
           localDnsResolver = false;
+          indexDir = "/var/lib/dovecot/indices";
 
           ldap = {
             enable = true;
@@ -104,6 +105,10 @@ pkgs.nixosTest {
             searchScope = "sub";
           };
 
+          forwards = {
+            "bob_fw@example.com" = "bob@example.com";
+          };
+
           vmailGroupName = "vmail";
           vmailUID = 5000;
 
@@ -111,7 +116,12 @@ pkgs.nixosTest {
         };
       };
   };
-  testScript = ''
+  testScript =
+    {
+      nodes,
+      ...
+    }:
+    ''
       import sys
       import re
 
@@ -147,7 +157,7 @@ pkgs.nixosTest {
         machine.succeed("ls -l /run/postfix/*.cf | grep -e '-rw------- 1 root root'")
         machine.succeed("ls -l /run/dovecot2/dovecot-ldap.conf.ext | grep -e '-rw------- 1 root root'")
 
-    with subtest("Test account/mail address binding"):
+      with subtest("Test account/mail address binding via explicit TLS"):
         machine.fail(" ".join([
           "mail-check send-and-read",
           "--smtp-port 587",
@@ -164,11 +174,11 @@ pkgs.nixosTest {
         ]))
         machine.succeed("journalctl -u postfix | grep -q 'Sender address rejected: not owned by user alice@example.com'")
 
-    with subtest("Test mail delivery"):
+      with subtest("Test mail delivery via implicit TLS"):
         machine.succeed(" ".join([
           "mail-check send-and-read",
-        "--smtp-port 587",
+          "--smtp-port 465",
-        "--smtp-starttls",
+          "--smtp-ssl",
           "--smtp-host localhost",
           "--smtp-username alice@example.com",
           "--imap-host localhost",
@@ -179,5 +189,43 @@ pkgs.nixosTest {
           "--dst-password-file <(echo '${bobPassword}')",
           "--ignore-dkim-spf"
         ]))
+
+      with subtest("Test mail forwarding via explicit TLS works"):
+        machine.succeed(" ".join([
+          "mail-check send-and-read",
+          "--smtp-port 587",
+          "--smtp-starttls",
+          "--smtp-host localhost",
+          "--smtp-username alice@example.com",
+          "--imap-host localhost",
+          "--imap-username bob@example.com",
+          "--from-addr alice@example.com",
+          "--to-addr bob_fw@example.com",
+          "--src-password-file <(echo '${alicePassword}')",
+          "--dst-password-file <(echo '${bobPassword}')",
+          "--ignore-dkim-spf"
+        ]))
+
+      with subtest("Test cannot send mail via implicit TLS from forwarded address"):
+        machine.fail(" ".join([
+          "mail-check send-and-read",
+          "--smtp-port 465",
+          "--smtp-ssl",
+          "--smtp-host localhost",
+          "--smtp-username bob@example.com",
+          "--imap-host localhost",
+          "--imap-username alice@example.com",
+          "--from-addr bob_fw@example.com",
+          "--to-addr alice@example.com",
+          "--src-password-file <(echo '${bobPassword}')",
+          "--dst-password-file <(echo '${alicePassword}')",
+          "--ignore-dkim-spf"
+        ]))
+        machine.succeed("journalctl -u postfix | grep -q 'Sender address rejected: not owned by user bob@example.com'")
+
+      with subtest("Check dovecot mail and index locations"):
+        # If these paths change we need a migration
+        machine.succeed("doveadm user -f home bob@example.com | grep ${nodes.machine.mailserver.mailDirectory}/ldap/bob@example.com")
+        machine.succeed("doveadm user -f mail bob@example.com | grep 'maildir:~/mail:INDEX=${nodes.machine.mailserver.indexDir}/ldap/bob@example.com'")
     '';
 }

tests/lib/config.nix

@@ -1,3 +1,28 @@
 {
-    security.dhparams.defaultBitSize = 1024; # minimum size required by dovecot
+  lib,
+  ...
+}:
+
+{
+  # Testing eval failures that result from stateVersion assertion is out of scope
+  mailserver.stateVersion = 999;
+
+  # Keep testing submission with explicit TLS
+  mailserver.enableSubmission = true;
+
+  # Enable second CPU core
+  virtualisation.cores = lib.mkDefault 2;
+
+  services.rspamd = {
+    # Don't make tests block on DNS requests that will never succeed
+    locals."options.inc".text = ''
+      dns {
+        nameservers = ["127.0.0.1"];
+        timeout = 0.0s;
+        retransmits = 0;
+      }
+    '';
+    # Relax `local_addrs` definition to default for tests, so mail doesn't get flagged as spam
+    overrides."options.inc".enable = false;
+  };
 }

tests/minimal.nix

@@ -1,31 +0,0 @@
-#  nixos-mailserver: a simple mail server
-#  Copyright (C) 2016-2018  Robin Raymond
-#
-#  This program is free software: you can redistribute it and/or modify
-#  it under the terms of the GNU General Public License as published by
-#  the Free Software Foundation, either version 3 of the License, or
-#  (at your option) any later version.
-#
-#  This program is distributed in the hope that it will be useful,
-#  but WITHOUT ANY WARRANTY; without even the implied warranty of
-#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-#  GNU General Public License for more details.
-#
-#  You should have received a copy of the GNU General Public License
-#  along with this program. If not, see <http://www.gnu.org/licenses/>
-
-import <nixpkgs/nixos/tests/make-test-python.nix> {
-
-  nodes.machine =
-    { config, pkgs, ... }:
-    {
-        imports = [
-            ./../default.nix
-        ];
-    };
-
-  testScript =
-    ''
-      machine.wait_for_unit("multi-user.target");
-    '';
-}

tests/multiple.nix

@@ -1,19 +1,34 @@
 # This tests is used to test features requiring several mail domains.
 
-{ pkgs ? import <nixpkgs> {}, ...}:
+{
+  lib,
+  pkgs,
+  ...
+}:
 
 let
-    hashPassword = password: pkgs.runCommand
+  hashPassword =
-      "password-${password}-hashed"
+    password:
-      { buildInputs = [ pkgs.mkpasswd ]; inherit password; }
+    pkgs.runCommand "password-${password}-hashed"
+      {
+        buildInputs = [ pkgs.mkpasswd ];
+        inherit password;
+      }
       ''
         mkpasswd -sm bcrypt <<<"$password" > $out
       '';
 
   password = pkgs.writeText "password" "password";
 
-    domainGenerator = domain: { config, pkgs, ... }: {
+  domainGenerator =
-      imports = [../default.nix];
+    domain:
+    { pkgs, ... }:
+    {
+      imports = [
+        ../default.nix
+        ./lib/config.nix
+      ];
+      environment.systemPackages = with pkgs; [ netcat ];
       virtualisation.memorySize = 1024;
       mailserver = {
         enable = true;
@@ -30,36 +45,49 @@ let
       };
       services.dnsmasq = {
         enable = true;
-        # Fixme: once nixos-22.11 has been removed, could be replaced by
+        settings.mx-host = [
-        # settings.mx-host = [ "domain1.com,domain1,10" "domain2.com,domain2,10" ];
+          "domain1.com,domain1,10"
-        extraConfig = ''
+          "domain2.com,domain2,10"
-          mx-host=domain1.com,domain1,10
+        ];
-          mx-host=domain2.com,domain2,10
-        '';
       };
+
+      # breaks the test, due to running into DNS timeouts
+      services.postfix-tlspol.configurePostfix = lib.mkForce false;
     };
 
 in
 
-pkgs.nixosTest {
+{
   name = "multiple";
+
   nodes = {
-    domain1 = {...}: {
+    domain1 =
+      { ... }:
+      {
         imports = [
           ../default.nix
           (domainGenerator "domain1.com")
         ];
         mailserver.forwards = {
-        "non-local@domain1.com" = ["user@domain2.com" "user@domain1.com"];
+          "non-local@domain1.com" = [
-        "non@domain1.com" = ["user@domain2.com" "user@domain1.com"];
+            "user@domain2.com"
+            "user@domain1.com"
+          ];
+          "non@domain1.com" = [
+            "user@domain2.com"
+            "user@domain1.com"
+          ];
         };
       };
     domain2 = domainGenerator "domain2.com";
-    client = { config, pkgs, ... }: {
+    client =
+      { pkgs, ... }:
+      {
         environment.systemPackages = [
           (pkgs.writeScriptBin "mail-check" ''
             ${pkgs.python3}/bin/python ${../scripts/mail-check.py} $@
-        '')];
+          '')
+        ];
       };
   };
   testScript = ''
@@ -70,20 +98,20 @@ pkgs.nixosTest {
 
     # TODO put this blocking into the systemd units?
     domain1.wait_until_succeeds(
-        "set +e; timeout 1 ${pkgs.netcat}/bin/nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
+        "set +e; timeout 1 nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
     )
     domain2.wait_until_succeeds(
-        "set +e; timeout 1 ${pkgs.netcat}/bin/nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
+        "set +e; timeout 1 nc -U /run/rspamd/rspamd-milter.sock < /dev/null; [ $? -eq 124 ]"
     )
 
-    # user@domain1.com sends a mail to user@domain2.com
+    # user@domain1.com sends a mail to user@domain2.com via explicit TLS
     client.succeed(
         "mail-check send-and-read --smtp-port 587 --smtp-starttls --smtp-host domain1 --from-addr user@domain1.com --imap-host domain2 --to-addr user@domain2.com --src-password-file ${password} --dst-password-file ${password} --ignore-dkim-spf"
     )
 
-    # Send a mail to the address forwarded and check it is in the recipient mailbox
+    # Send a mail to the address forwarded via implicit TLS and check it is in the recipient mailbox
     client.succeed(
-        "mail-check send-and-read --smtp-port 587 --smtp-starttls --smtp-host domain1 --from-addr user@domain1.com --imap-host domain2 --to-addr non-local@domain1.com --imap-username user@domain2.com --src-password-file ${password} --dst-password-file ${password} --ignore-dkim-spf"
+        "mail-check send-and-read --smtp-port 465 --smtp-ssl --smtp-host domain1 --from-addr user@domain1.com --imap-host domain2 --to-addr non-local@domain1.com --imap-username user@domain2.com --src-password-file ${password} --dst-password-file ${password} --ignore-dkim-spf"
     )
   '';
 }

update.sh

@@ -1,7 +0,0 @@
-#!/usr/bin/env bash
-
-sed -i -e "s/v[0-9]\+\.[0-9]\+\.[0-9]\+/$1/g" README.md
-
-HASH=$(nix-prefetch-url "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/v2.3.0/nixos-mailserver-$1.tar.gz" --unpack)
-
-sed -i -e "s/sha256 = \"[0-9a-z]\{52\}\"/sha256 = \"$HASH\"/g" README.md