This article was previously published under Q314734
After you set mail relaying restrictions on the default Simple Mail Transport Protocol (SMTP) virtual server, the restrictions may not work. If you then set restrictions to prevent all mail relays for Authenticated Users, the restrictions still may not work.
This behavior can occur if you configure your SMTP connector to allow relaying. This setting overrides all restrictions on the default virtual SMTP server.
To resolve this behavior, turn off relaying:
In Exchange System Manager (ESM), right-click the SMTP connector, and then click Properties.
Click the Address Space tab, and then click to clear the Allow messages to be relayed to these Domains check box.