diff --git a/seqs/mailserver.sh b/seqs/mailserver.sh
index 9a77710..425290e 100755
--- a/seqs/mailserver.sh
+++ b/seqs/mailserver.sh
@@ -296,6 +296,7 @@ step_25() {
   echo
   echo "# Enable sieve for lmtp"
   echo "  [$mdaConfDir/20-lmtp.conf]"
+  echo "   postmaster_address = postmaster@$MAS_DOMAIN"
   echo "   mail_plugins = $mail_plugins sieve"
 }