diff --git a/nixos/doc/manual/release-notes/rl-2311.section.md b/nixos/doc/manual/release-notes/rl-2311.section.md
index d7fe84cbf70e..3083141e77f6 100644
--- a/nixos/doc/manual/release-notes/rl-2311.section.md
+++ b/nixos/doc/manual/release-notes/rl-2311.section.md
@@ -983,8 +983,7 @@ Make sure to also check the many updates in the [Nixpkgs library](#sec-release-2
   [services.sitespeed-io](#opt-services.sitespeed-io.enable).
 
 - [stalwart-mail](https://stalw.art), an all-in-one email server (SMTP, IMAP,
-  JMAP). Available as
-  [services.stalwart-mail](#opt-services.stalwart-mail.enable).
+  JMAP). Available as `services.stalwart-mail`.
 
 
 - [tang](https://github.com/latchset/tang), a server for binding data to
diff --git a/nixos/doc/manual/release-notes/rl-2405.section.md b/nixos/doc/manual/release-notes/rl-2405.section.md
index 7f2e0f622c62..9f0bab8129af 100644
--- a/nixos/doc/manual/release-notes/rl-2405.section.md
+++ b/nixos/doc/manual/release-notes/rl-2405.section.md
@@ -741,7 +741,7 @@ Use `services.pipewire.extraConfig` or `services.pipewire.configPackages` for Pi
 
 - `services.soju` now has a wrapper for the `sojuctl` command, pointed at the service config file. It also has the new option `adminSocket.enable`, which creates a unix admin socket at `/run/soju/admin`.
 
-- `services.stalwart-mail` uses the legacy version 0.6.X as default because newer `stalwart-mail` versions require a [manual upgrade process](https://github.com/stalwartlabs/mail-server/blob/main/UPGRADING.md). Change [`services.stalwart-mail.package`](#opt-services.stalwart-mail.package) to `pkgs.stalwart-mail` if you wish to switch to the new version.
+- `services.stalwart-mail` uses the legacy version 0.6.X as default because newer `stalwart-mail` versions require a [manual upgrade process](https://github.com/stalwartlabs/mail-server/blob/main/UPGRADING.md). Change `services.stalwart-mail.package` to `pkgs.stalwart-mail` if you wish to switch to the new version.
 
 - `services.teeworlds` module now has a wealth of configuration options, including a new `package` option.
 
diff --git a/nixos/doc/manual/release-notes/rl-2411.section.md b/nixos/doc/manual/release-notes/rl-2411.section.md
index 28cc21b77b4d..10392e1dea75 100644
--- a/nixos/doc/manual/release-notes/rl-2411.section.md
+++ b/nixos/doc/manual/release-notes/rl-2411.section.md
@@ -508,8 +508,7 @@
 
 - Legacy package `stalwart-mail_0_6` was dropped, please note the
   [manual upgrade process](https://github.com/stalwartlabs/mail-server/blob/main/UPGRADING.md)
-  before changing the package to `pkgs.stalwart-mail` in
-  [`services.stalwart-mail.package`](#opt-services.stalwart-mail.package).
+  before changing the package to `pkgs.stalwart-mail` in `services.stalwart-mail.package`.
 
 - `nomad_1_5` and `nomad_1_6` were dropped, as [they have reached end-of-life upstream](https://support.hashicorp.com/hc/en-us/articles/360021185113-Support-Period-and-End-of-Life-EOL-Policy). Evaluating them will throw an error.
 
diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
index a6913729e510..b6c19e8cc5de 100644
--- a/nixos/modules/module-list.nix
+++ b/nixos/modules/module-list.nix
@@ -778,7 +778,7 @@
   ./services/mail/rss2email.nix
   ./services/mail/schleuder.nix
   ./services/mail/spamassassin.nix
-  ./services/mail/stalwart-mail.nix
+  ./services/mail/stalwart.nix
   ./services/mail/sympa.nix
   ./services/mail/tlsrpt.nix
   ./services/mail/zeyple.nix
diff --git a/nixos/modules/services/mail/stalwart-mail.nix b/nixos/modules/services/mail/stalwart.nix
similarity index 84%
rename from nixos/modules/services/mail/stalwart-mail.nix
rename to nixos/modules/services/mail/stalwart.nix
index a0ea04e50a14..5d1263bd794d 100644
--- a/nixos/modules/services/mail/stalwart-mail.nix
+++ b/nixos/modules/services/mail/stalwart.nix
@@ -5,9 +5,9 @@
   ...
 }:
 let
-  cfg = config.services.stalwart-mail;
+  cfg = config.services.stalwart;
   configFormat = pkgs.formats.toml { };
-  configFile = configFormat.generate "stalwart-mail.toml" cfg.settings;
+  configFile = configFormat.generate "stalwart.toml" cfg.settings;
   useLegacyStorage = lib.versionOlder config.system.stateVersion "24.11";
 
   parsePorts =
@@ -21,17 +21,22 @@ let
 
 in
 {
-  options.services.stalwart-mail = {
-    enable = lib.mkEnableOption "the Stalwart all-in-one email server";
+  imports = [
+    # since 0.12.0 (2025-05-26) release, upstream re-branded project to 'stalwart' due to inclusion of collaboration features (CalDAV, CardDAV, and WebDAV)
+    #  https://github.com/stalwartlabs/stalwart/releases/tag/v0.12.0
+    (lib.mkRenamedOptionModule [ "services" "stalwart-mail" ] [ "services" "stalwart" ])
+  ];
+  options.services.stalwart = {
+    enable = lib.mkEnableOption "the all-in-one collaboration and mail server, Stalwart";
 
-    package = lib.mkPackageOption pkgs "stalwart-mail" { };
+    package = lib.mkPackageOption pkgs "stalwart" { };
 
     openFirewall = lib.mkOption {
       type = lib.types.bool;
       default = false;
       description = ''
         Whether to open TCP firewall ports, which are specified in
-        {option}`services.stalwart-mail.settings.server.listener` on all interfaces.
+        {option}`services.stalwart.settings.server.listener` on all interfaces.
       '';
     };
 
@@ -39,7 +44,7 @@ in
       inherit (configFormat) type;
       default = { };
       description = ''
-        Configuration options for the Stalwart email server.
+        Configuration options for the Stalwart collaboration and e-mail server.
         See <https://stalw.art/docs/category/configuration> for available options.
 
         By default, the module is configured to store everything locally.
@@ -48,7 +53,7 @@ in
 
     dataDir = lib.mkOption {
       type = lib.types.path;
-      default = "/var/lib/stalwart-mail";
+      default = "/var/lib/stalwart";
       description = ''
         Data directory for stalwart
       '';
@@ -56,10 +61,10 @@ in
 
     credentials = lib.mkOption {
       description = ''
-        Credentials envs used to configure Stalwart-Mail secrets.
+        Credentials envs used to configure Stalwart secrets.
         These secrets can be accessed in configuration values with
         the macros such as
-        `%{file:/run/credentials/stalwart-mail.service/VAR_NAME}%`.
+        `%{file:/run/credentials/stalwart.service/VAR_NAME}%`.
       '';
       type = lib.types.attrsOf lib.types.str;
       default = { };
@@ -90,7 +95,7 @@ in
     ];
 
     # Default config: all local
-    services.stalwart-mail.settings = {
+    services.stalwart.settings = {
       tracer.stdout = {
         type = lib.mkDefault "stdout";
         level = lib.mkDefault "info";
@@ -132,7 +137,7 @@ in
           );
         in
         {
-          path = "/var/cache/stalwart-mail";
+          path = "/var/cache/stalwart";
           resource = lib.mkIf hasHttpListener (lib.mkDefault "file://${cfg.package.webadmin}/webadmin.zip");
         };
     };
@@ -142,20 +147,20 @@ in
     # service is restarted on a potentially large number of files.
     # That would cause unnecessary and unwanted delays.
     users = {
-      groups.stalwart-mail = { };
-      users.stalwart-mail = {
+      groups.stalwart = { };
+      users.stalwart = {
         isSystemUser = true;
-        group = "stalwart-mail";
+        group = "stalwart";
       };
     };
 
     systemd.tmpfiles.rules = [
-      "d '${cfg.dataDir}' - stalwart-mail stalwart-mail - -"
+      "d '${cfg.dataDir}' - stalwart stalwart - -"
     ];
 
     systemd = {
       services.stalwart-mail = {
-        description = "Stalwart Mail Server";
+        description = "Stalwart Server";
         wantedBy = [ "multi-user.target" ];
         after = [
           "local-fs.target"
@@ -170,7 +175,7 @@ in
           KillSignal = "SIGINT";
           Restart = "on-failure";
           RestartSec = 5;
-          SyslogIdentifier = "stalwart-mail";
+          SyslogIdentifier = "stalwart";
 
           ExecStartPre =
             if useLegacyStorage then
@@ -190,12 +195,12 @@ in
           ReadWritePaths = [
             cfg.dataDir
           ];
-          CacheDirectory = "stalwart-mail";
-          StateDirectory = "stalwart-mail";
+          CacheDirectory = "stalwart";
+          StateDirectory = "stalwart";
 
           # Upstream uses "stalwart" as the username since 0.12.0
-          User = "stalwart-mail";
-          Group = "stalwart-mail";
+          User = "stalwart";
+          Group = "stalwart";
 
           # Bind standard privileged ports
           AmbientCapabilities = [ "CAP_NET_BIND_SERVICE" ];
diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index 50c27ec6da79..ee3bf21b8211 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -1477,7 +1477,7 @@ in
   sslh = handleTest ./sslh.nix { };
   sssd-ldap = handleTestOn [ "x86_64-linux" "aarch64-linux" ] ./sssd-ldap.nix { };
   sssd-legacy-config = handleTestOn [ "x86_64-linux" "aarch64-linux" ] ./sssd-legacy-config.nix { };
-  stalwart-mail = runTest ./stalwart/stalwart-mail.nix;
+  stalwart = runTest ./stalwart/stalwart.nix;
   stargazer = runTest ./web-servers/stargazer.nix;
   starship = runTest ./starship.nix;
   startx = import ./startx.nix { inherit pkgs runTest; };
diff --git a/nixos/tests/stalwart/stalwart-mail-config.nix b/nixos/tests/stalwart/stalwart-config.nix
similarity index 98%
rename from nixos/tests/stalwart/stalwart-mail-config.nix
rename to nixos/tests/stalwart/stalwart-config.nix
index cb2989033763..343f7d9caab8 100644
--- a/nixos/tests/stalwart/stalwart-mail-config.nix
+++ b/nixos/tests/stalwart/stalwart-config.nix
@@ -7,7 +7,7 @@ in
 {
   security.pki.certificateFiles = [ certs.ca.cert ];
 
-  services.stalwart-mail = {
+  services.stalwart = {
     enable = true;
     settings = {
       server.hostname = domain;
diff --git a/nixos/tests/stalwart/stalwart-mail.nix b/nixos/tests/stalwart/stalwart.nix
similarity index 86%
rename from nixos/tests/stalwart/stalwart-mail.nix
rename to nixos/tests/stalwart/stalwart.nix
index 6466e648d626..79d1e3415c20 100644
--- a/nixos/tests/stalwart/stalwart-mail.nix
+++ b/nixos/tests/stalwart/stalwart.nix
@@ -1,4 +1,4 @@
-# Rudimentary test checking that the Stalwart email server can:
+# Rudimentary test checking that the Stalwart collaboration server can:
 # - receive some message through SMTP submission, then
 # - serve this message through IMAP.
 
@@ -8,13 +8,13 @@ let
 in
 { lib, ... }:
 {
-  name = "stalwart-mail";
+  name = "stalwart";
 
   nodes.main =
     { pkgs, ... }:
     {
       imports = [
-        ./stalwart-mail-config.nix
+        ./stalwart-config.nix
       ];
 
       environment.systemPackages = [
@@ -57,7 +57,7 @@ in
 
   testScript = # python
     ''
-      main.wait_for_unit("stalwart-mail.service")
+      main.wait_for_unit("stalwart.service")
       main.wait_for_open_port(587)
       main.wait_for_open_port(143)
       main.wait_for_open_port(80)
@@ -65,14 +65,14 @@ in
       main.succeed("test-smtp-submission")
 
       # restart stalwart to test rocksdb compaction of existing database
-      main.succeed("systemctl restart stalwart-mail.service")
+      main.succeed("systemctl restart stalwart.service")
       main.wait_for_open_port(587)
       main.wait_for_open_port(143)
       main.wait_for_open_port(80)
 
       main.succeed("test-imap-read")
 
-      main.succeed("test -d /var/cache/stalwart-mail/STALWART_WEBADMIN")
+      main.succeed("test -d /var/cache/stalwart/STALWART_WEBADMIN")
       main.succeed("curl --fail http://localhost")
     '';
 
diff --git a/pkgs/by-name/st/stalwart-cli/package.nix b/pkgs/by-name/st/stalwart-cli/package.nix
index 4c9d813e7a2f..4c03d8b3b512 100644
--- a/pkgs/by-name/st/stalwart-cli/package.nix
+++ b/pkgs/by-name/st/stalwart-cli/package.nix
@@ -2,11 +2,11 @@
   lib,
   rustPlatform,
   versionCheckHook,
-  stalwart-mail,
+  stalwart,
 }:
 
 rustPlatform.buildRustPackage {
-  inherit (stalwart-mail) src version cargoDeps;
+  inherit (stalwart) src version cargoDeps;
   pname = "stalwart-cli";
 
   cargoBuildFlags = [
@@ -25,7 +25,7 @@ rustPlatform.buildRustPackage {
   dontVersionCheck = true;
 
   meta = {
-    inherit (stalwart-mail.meta) license homepage changelog;
+    inherit (stalwart.meta) license homepage changelog;
     description = "Stalwart Mail Server CLI";
     mainProgram = "stalwart-cli";
     maintainers = with lib.maintainers; [
diff --git a/pkgs/by-name/st/stalwart-mail/package.nix b/pkgs/by-name/st/stalwart/package.nix
similarity index 93%
rename from pkgs/by-name/st/stalwart-mail/package.nix
rename to pkgs/by-name/st/stalwart/package.nix
index 4be73405bd7e..84cbea33885f 100644
--- a/pkgs/by-name/st/stalwart-mail/package.nix
+++ b/pkgs/by-name/st/stalwart/package.nix
@@ -20,7 +20,7 @@
 }:
 
 rustPlatform.buildRustPackage (finalAttrs: {
-  pname = "stalwart-mail" + (lib.optionalString stalwartEnterprise "-enterprise");
+  pname = "stalwart" + (lib.optionalString stalwartEnterprise "-enterprise");
   version = "0.15.4";
 
   src = fetchFromGitHub {
@@ -87,7 +87,7 @@ rustPlatform.buildRustPackage (finalAttrs: {
 
     mkdir -p $out/lib/systemd/system
 
-    substitute resources/systemd/stalwart-mail.service $out/lib/systemd/system/stalwart-mail.service \
+    substitute resources/systemd/stalwart-mail.service $out/lib/systemd/system/stalwart.service \
       --replace-fail "__PATH__" "$out"
   '';
 
@@ -185,20 +185,20 @@ rustPlatform.buildRustPackage (finalAttrs: {
     webadmin = buildPackages.callPackage ./webadmin.nix { };
     spam-filter = callPackage ./spam-filter.nix { };
     updateScript = nix-update-script { };
-    tests.stalwart-mail = nixosTests.stalwart-mail;
+    tests.stalwart = nixosTests.stalwart;
   };
 
   meta = {
-    description = "Secure & Modern All-in-One Mail Server (IMAP, JMAP, SMTP)";
-    homepage = "https://github.com/stalwartlabs/mail-server";
-    changelog = "https://github.com/stalwartlabs/mail-server/blob/main/CHANGELOG.md";
+    description = "Secure, modern, and all-in-one mail & collaboration server fluent in IMAP, JMAP, SMTP, CalDAV, CardDAV, and WebDAV";
+    homepage = "https://github.com/stalwartlabs/stalwart";
+    changelog = "https://github.com/stalwartlabs/stalwart/blob/main/CHANGELOG.md";
     license = [
       lib.licenses.agpl3Only
     ]
     ++ lib.optionals stalwartEnterprise [
       {
         fullName = "Stalwart Enterprise License 1.0 (SELv1) Agreement";
-        url = "https://github.com/stalwartlabs/mail-server/blob/main/LICENSES/LicenseRef-SEL.txt";
+        url = "https://github.com/stalwartlabs/stalwart/blob/main/LICENSES/LicenseRef-SEL.txt";
         free = false;
         redistributable = false;
       }
diff --git a/pkgs/by-name/st/stalwart-mail/spam-filter.nix b/pkgs/by-name/st/stalwart/spam-filter.nix
similarity index 82%
rename from pkgs/by-name/st/stalwart-mail/spam-filter.nix
rename to pkgs/by-name/st/stalwart/spam-filter.nix
index 95fc5e43035c..68f638a11aa4 100644
--- a/pkgs/by-name/st/stalwart-mail/spam-filter.nix
+++ b/pkgs/by-name/st/stalwart/spam-filter.nix
@@ -2,7 +2,7 @@
   lib,
   fetchFromGitHub,
   stdenv,
-  stalwart-mail,
+  stalwart,
   nix-update-script,
 }:
 
@@ -31,13 +31,13 @@ stdenv.mkDerivation (finalAttrs: {
   };
 
   meta = {
-    description = "Secure & modern all-in-one mail server Stalwart (spam-filter module)";
+    description = "Secure, modern, and all-in-one mail & collaboration server, Stalwart (spam-filter module)";
     homepage = "https://github.com/stalwartlabs/spam-filter";
     changelog = "https://github.com/stalwartlabs/spam-filter/blob/${finalAttrs.src.tag}/CHANGELOG.md";
     license = with lib.licenses; [
       mit
       asl20
     ];
-    inherit (stalwart-mail.meta) maintainers;
+    inherit (stalwart.meta) maintainers;
   };
 })
diff --git a/pkgs/by-name/st/stalwart-mail/webadmin.nix b/pkgs/by-name/st/stalwart/webadmin.nix
similarity index 90%
rename from pkgs/by-name/st/stalwart-mail/webadmin.nix
rename to pkgs/by-name/st/stalwart/webadmin.nix
index e77e8ba4c90d..a61847f30acb 100644
--- a/pkgs/by-name/st/stalwart-mail/webadmin.nix
+++ b/pkgs/by-name/st/stalwart/webadmin.nix
@@ -1,7 +1,7 @@
 {
   lib,
   rustPlatform,
-  stalwart-mail,
+  stalwart,
   fetchFromGitHub,
   trunk,
   tailwindcss_3,
@@ -68,10 +68,10 @@ rustPlatform.buildRustPackage (finalAttrs: {
   };
 
   meta = {
-    description = "Secure & modern all-in-one mail server Stalwart (webadmin module)";
+    description = "Secure, modern, and all-in-one mail & collaboration server, Stalwart (webadmin module)";
     homepage = "https://github.com/stalwartlabs/webadmin";
     changelog = "https://github.com/stalwartlabs/webadmin/blob/${finalAttrs.src.tag}/CHANGELOG.md";
     license = lib.licenses.agpl3Only;
-    inherit (stalwart-mail.meta) maintainers;
+    inherit (stalwart.meta) maintainers;
   };
 })
diff --git a/pkgs/top-level/aliases.nix b/pkgs/top-level/aliases.nix
index d394294c8125..7c9754b8ef01 100644
--- a/pkgs/top-level/aliases.nix
+++ b/pkgs/top-level/aliases.nix
@@ -1662,6 +1662,7 @@ mapAliases {
   src = throw "The \"src\" package has been renamed to \"simple-revision-control\". If you encounter this error and did not intend to use that package you may have a falsely constructed overlay."; # Added 2025-11-19
   ssm-agent = throw "'ssm-agent' has been renamed to/replaced by 'amazon-ssm-agent'"; # Converted to throw 2025-10-27
   stacer = throw "'stacer' has been removed because it was abandoned upstream and relied upon vulnerable software"; # Added 2025-11-08
+  stalwart-mail = warnAlias "'stalwart-mail' has been renamed to/replaced by 'stalwart'" stalwart; # Added 2026-01-19
   starpls-bin = throw "'starpls-bin' has been renamed to/replaced by 'starpls'"; # Converted to throw 2025-10-27
   station = throw "station has been removed from nixpkgs, as there were no committers among its maintainers to unblock security issues"; # Added 2025-06-16
   steam-run-native = throw "'steam-run-native' has been renamed to/replaced by 'steam-run'"; # Converted to throw 2025-10-27
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 7d3d396b73cc..1978829a973b 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -8982,10 +8982,10 @@ with pkgs;
     enableAirplay2 = true;
   };
 
-  stalwart-mail-webadmin = stalwart-mail.webadmin;
-  stalwart-mail-spam-filter = stalwart-mail.spam-filter;
+  stalwart-webadmin = stalwart.webadmin;
+  stalwart-spam-filter = stalwart.spam-filter;
 
-  stalwart-mail-enterprise = stalwart-mail.override {
+  stalwart-enterprise = stalwart.override {
     stalwartEnterprise = true;
   };