I've got all messages sent to my Exchange Server (5.5 SP3) bouncing back with 550 Recipient not local. I know it's supposed to be a routing issue in Internet Mail Services, but I've tried all different combinations in there. Currently, Reroute Incoming SMTP mail is checked with my domain name in the route to box, accepted as incoming mail. I've stopped and restarted Internet Mail Services to no avail. I've also reinstalled Exchange - same results. Our DNS'ing is done at our ISP so let me know if that could be related.