Fix #9759 SSMTP sendmail wrapper

nixos/modules/programs/ssmtp.nix

@@ -101,6 +101,12 @@ in
         '';
       };
       
+      setSendmail = mkOption {
+        type = types.bool;
+        default = true;
+        description = "Whether to set the system sendmail to ssmtp's.";
+      };
+
     };
 
   };
@@ -123,6 +129,13 @@ in
 
     environment.systemPackages = [pkgs.ssmtp];
     
+    services.mail.sendmailSetuidWrapper = mkIf networking.defaultMailServer.setSendmail {
+      program = "sendmail";
+      source = "${pkgs.ssmtp}/bin/sendmail";
+      setuid = false;
+      setgid = false;
+    };
+
   };
 
 }