Enable redirections to sender and disable loop detection

flake-module.nix

@@ -1,4 +1,8 @@
-{inputs, ...}: {
+{
+  inputs,
+  lib,
+  ...
+}: {
   # debug = true;
   # We only define machines config in this flake yet, so we only include
   # the module that builds these. This file might get fuller, if we need to
@@ -55,8 +59,22 @@
       config.permittedInsecurePackages = ["jitsi-meet-1.0.8043"];
 
       overlays = [
-        (_: _: {
+        (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") "Copy the Cargo.lock file from upstream and reintroduce the patch to sieve-rs, then update this assert statement.";
+            prev.stalwart-mail.overrideAttrs (
+              finalAttrs: prevAttrs:
+                prevAttrs
+                // rec {
+                  cargoDeps = final.rustPlatform.importCargoLock {
+                    lockFile = ./Cargo.lock;
+                  };
+                  postPatch = ''
+                    cp ${./Cargo.lock} Cargo.lock
+                  '';
+                  cargoHash = "";
+                }
+            );
         })
       ];
     };