Sorry for the "off the topic" question but no one else can answer this question, so I'm turning to the PROS! (Using exchange 5.5 sp4) When an outside e-mail comes to our domain and it is not correctly addressed to the user's e-mail box (EX: JOE@xxxxxxxx but they typed JEO@xxxxxxxx ), the sender doesn't get a undeliverable notice. So to them it seem that it has gone through, but it ends up in the bit bucket. Any thoughts on how to set the notify level in Exchange 5.5 so the sender gets notice that it did not go through? John