diff --git a/config.yaml.example b/config.yaml.example
index 8887942..7a47371 100644
--- a/config.yaml.example
+++ b/config.yaml.example
@@ -7,7 +7,7 @@ mail_config:
   smtp_host: localhost
   smtp_port: 25
   base_url: https://motions.cacert.org
-  domain: motions.cacert.org
+  message_id_domain: motions.cacert.org
   notice_mail_address: cacert-board@lists.cacert.org
   vote_notice_mail_address: cacert-board-votes@lists.cacert.org
   notification_sender_address: returns@cacert.org