I'm getting an error when runnign the Mailflow troubleshooter in Exchange 2007. I'm also running Exchange 2003 currently (although I plan on removing it once I get 2007). I have checked everything I can find. The one thing to note is that I don't have the public IP entered in my NIC settings yet (waiting to get one mailbox working internally...hopefully if it's even possible?) I can send mail using a given account that we'll call News. But I can't receive mail in News. I tested this morning but turning our 2003 server off and adding in the public IPs, but then I could receive, but not send. I've tried everything i can find. I can telnet on port 25. I think it's going to be something simple and a one click change....just can't figure it out. Thanks!