Enable redirects to sender using less own repositories

flake-module.nix

@@ -59,7 +59,7 @@
       config.permittedInsecurePackages = ["jitsi-meet-1.0.8043"];
 
       overlays = [
-        (_: prev: {
+        (final: prev: {
           alias-to-sieve = inputs.alias-to-sieve.packages.x86_64-linux.default; # add custom package to convert alias files to sieve scripts on the stalwart machine
           stalwart-mail = assert lib.assertMsg (prev.stalwart-mail.version == "0.11.6-unstable-2025-02-04") ''
             1. If the bug https://github.com/stalwartlabs/sieve/issues/11 is resolved to our satisfaction, try to remove this overlay.
@@ -67,7 +67,6 @@
             3. Check whether the sieve-rs patch below that exchanges the dependency needs updates.
             4. Then update the version comparison in this assert statement.
             5. Update the `cargoHash` by setting it to `lib.fakeHash` and then inserting the result.
-            6. Check if we can get rid of alias-to-sieve when stalwart-mail has a builtin alias feature.
           '';
             prev.stalwart-mail.override (
               let