Ok, here's one for all of you. I'm having difficulty sending email to one domain, ameritech.net. My stats are: W2K server, E2k sp2, DNS hosted on site, DSL connection. The emails that are sent to ameritech.net are timing out in the queue, and coming up with a 4.4.7 error. My server is not a relay, so I can rule that out. This is the only domain that I have this happen with. I would like to think that it is not my setup, since no other domains have this problem. Is it possible that ameritech.net is performing some sort of reverse lookup on messages to prevent spam to their customers that my server is not passing? Any help would be great. I'm not the biggest Exchange expert, but I can get along. However, I can't seem to find anything wrong with my setup. Thanks in advance, Chris