I've heard of this problem on another list. Presumably if it's getting widespread notice there will be a fix soon. Have you tried adding the IP of the machine that generates the message to the Perimeter IP and Internal IP list (Message delivery General tab)? Carl -----Original Message----- From: Simon Bound [mailto:simon.bound@xxxxxxxxxxxxxxxxxxxx] Sent: Tuesday, November 22, 2005 6:44 AM To: [ExchangeList] Subject: [exchangelist] IMF and Backup Exec Here's a good one perhaps !! In an attempt to tighten clients spam up I've implemented IMF which is working very well. However I have found it is blocking Backup Exec SMTP notifications being sent out. Can someone enlighten me how to get over this problem ? I'm somewhat confused due to the fact I'm sending and receiving on the same box (SBS 2003). Simon