diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
index 918d0f3b245..e0e806e690d 100644
--- a/nixos/modules/module-list.nix
+++ b/nixos/modules/module-list.nix
@@ -263,6 +263,7 @@
   ./services/mail/offlineimap.nix
   ./services/mail/opendkim.nix
   ./services/mail/opensmtpd.nix
+  ./services/mail/pfix-srsd.nix
   ./services/mail/postfix.nix
   ./services/mail/postsrsd.nix
   ./services/mail/postgrey.nix
diff --git a/nixos/modules/services/mail/pfix-srsd.nix b/nixos/modules/services/mail/pfix-srsd.nix
new file mode 100644
index 00000000000..ab5f4c39e8c
--- /dev/null
+++ b/nixos/modules/services/mail/pfix-srsd.nix
@@ -0,0 +1,56 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+{
+
+  ###### interface
+
+  options = {
+
+    services.pfix-srsd = {
+      enable = mkOption {
+        default = false;
+        type = types.bool;
+        description = "Whether to run the postfix sender rewriting scheme daemon.";
+      };
+
+      domain = mkOption {
+        description = "The domain for which to enable srs";
+        type = types.str;
+        example = "example.com";
+      };
+
+      secretsFile = mkOption {
+        description = ''
+          The secret data used to encode the SRS address.
+          to generate, use a command like:
+          <literal>for n in $(seq 5); do dd if=/dev/urandom count=1 bs=1024 status=none | sha256sum | sed 's/  -$//' | sed 's/^/          /'; done</literal>
+        '';
+        type = types.path;
+        default = "/var/lib/pfix-srsd/secrets";
+      };
+    };
+  };
+
+  ###### implementation
+
+  config = mkIf config.services.pfix-srsd.enable {
+    environment = {
+      systemPackages = [ pkgs.pfixtools ];
+    };
+
+    systemd.services."pfix-srsd" = {
+      description = "Postfix sender rewriting scheme daemon";
+      before = [ "postfix.service" ];
+      #note that we use requires rather than wants because postfix
+      #is unable to process (almost) all mail without srsd
+      requiredBy = [ "postfix.service" ];
+      serviceConfig = {
+        Type = "forking";
+        PIDFile = "/var/run/pfix-srsd.pid";
+        ExecStart = "${pkgs.pfixtools}/bin/pfix-srsd -p /var/run/pfix-srsd.pid -I ${config.services.pfix-srsd.domain} ${config.services.pfix-srsd.secretsFile}";
+      };
+    };
+  };
+}
\ No newline at end of file
diff --git a/nixos/modules/services/mail/postfix.nix b/nixos/modules/services/mail/postfix.nix
index 01ae49d4909..461d4a62138 100644
--- a/nixos/modules/services/mail/postfix.nix
+++ b/nixos/modules/services/mail/postfix.nix
@@ -79,6 +79,12 @@ let
   // optionalAttrs haveTransport { transport_maps = "hash:/etc/postfix/transport"; }
   // optionalAttrs haveVirtual { virtual_alias_maps = "${cfg.virtualMapType}:/etc/postfix/virtual"; }
   // optionalAttrs (cfg.dnsBlacklists != []) { smtpd_client_restrictions = clientRestrictions; }
+  // optionalAttrs cfg.useSrs {
+    sender_canonical_maps = "tcp:127.0.0.1:10001";
+    sender_canonical_classes = "envelope_sender";
+    recipient_canonical_maps = "tcp:127.0.0.1:10002";
+    recipient_canonical_classes= "envelope_recipient";
+  }
   // optionalAttrs cfg.enableHeaderChecks { header_checks = "regexp:/etc/postfix/header_checks"; }
   // optionalAttrs (cfg.sslCert != "") {
     smtp_tls_CAfile = cfg.sslCACert;
@@ -626,6 +632,12 @@ in
         description = "Maps to be compiled and placed into /var/lib/postfix/conf.";
       };
 
+      useSrs = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Whether to enable sender rewriting scheme";
+      };
+
     };
 
   };
@@ -646,6 +658,8 @@ in
         systemPackages = [ pkgs.postfix ];
       };
 
+      services.pfix-srsd.enable = config.services.postfix.useSrs;
+
       services.mail.sendmailSetuidWrapper = mkIf config.services.postfix.setSendmail {
         program = "sendmail";
         source = "${pkgs.postfix}/bin/sendmail";