diff --git a/nixos/modules/services/mail/stalwart-mail.nix b/nixos/modules/services/mail/stalwart-mail.nix
index 9cc919fd117d..08b07b885b69 100644
--- a/nixos/modules/services/mail/stalwart-mail.nix
+++ b/nixos/modules/services/mail/stalwart-mail.nix
@@ -38,6 +38,7 @@ in {
       store.blob.path = mkDefault "${dataDir}/data/blobs";
       storage.data = mkDefault "db";
       storage.fts = mkDefault "db";
+      storage.lookup = mkDefault "db";
       storage.blob = mkDefault "blob";
       resolver.type = mkDefault "system";
       resolver.public-suffix = mkDefault ["https://publicsuffix.org/list/public_suffix_list.dat"];
diff --git a/nixos/tests/stalwart-mail.nix b/nixos/tests/stalwart-mail.nix
index 634c0e2e3926..581090cd70f4 100644
--- a/nixos/tests/stalwart-mail.nix
+++ b/nixos/tests/stalwart-mail.nix
@@ -40,12 +40,14 @@ in import ./make-test-python.nix ({ lib, ... }: {
           };
         };
 
-        session.auth.mechanisms = [ "PLAIN" ];
-        session.auth.directory = "in-memory";
-        storage.directory = "in-memory";  # shared with imap
+        resolver.public-suffix = [ ];  # do not fetch from web in sandbox
 
-        session.rcpt.directory = "in-memory";
-        queue.outbound.next-hop = [ "local" ];
+        session.auth.mechanisms = "[plain]";
+        session.auth.directory = "'in-memory'";
+        storage.directory = "in-memory";
+
+        session.rcpt.directory = "'in-memory'";
+        queue.outbound.next-hop = "'local'";
 
         directory."in-memory" = {
           type = "memory";
diff --git a/pkgs/servers/mail/stalwart/default.nix b/pkgs/servers/mail/stalwart/default.nix
index 44b2251ce0c7..be0d9109fa75 100644
--- a/pkgs/servers/mail/stalwart/default.nix
+++ b/pkgs/servers/mail/stalwart/default.nix
@@ -10,6 +10,7 @@
 , stdenv
 , darwin
 , nix-update-script
+, nixosTests
 , rocksdb_8_3
 }:
 
@@ -60,7 +61,10 @@ rustPlatform.buildRustPackage {
   # Tests require reading to /etc/resolv.conf
   doCheck = false;
 
-  passthru.update-script = nix-update-script { };
+  passthru = {
+    update-script = nix-update-script { };
+    stalwart-mail = nixosTests.stalwart-mail;
+  };
 
   meta = with lib; {
     description = "Secure & Modern All-in-One Mail Server (IMAP, JMAP, SMTP)";