diff --git a/modules/mailserver.nix b/modules/mailserver.nix
index 2ac0818..8ef9056 100644
--- a/modules/mailserver.nix
+++ b/modules/mailserver.nix
@@ -479,6 +479,16 @@ in
         "milter_headers.conf".text = ''
           extended_spam_headers = true;
         '';
+        "multimap.conf".text = ''
+          SENDER_DOMAIN_BLOCKED {
+            type = "from";
+            filter = "email:domain:tld";
+            map = "/var/lib/rspamd/blocked_sender_domains.map";
+            symbol = "SENDER_DOMAIN_BLOCKED";
+            description = "Sender’s effective second level domain is manually blocked";
+            score = 8.0;
+          }
+        '';
         "redis.conf".text = ''
           servers = "127.0.0.1:${toString config.services.redis.servers.rspamd.port}"
         '';