Windows Server 2003 Small Business Edition SP2. Email appears to be arriving intermittently. They are not bouncing back from any IP or generating any undeliverable messages. People are saying they've sent messages, but on our side, they were never received. Some are though. It's very intermittent. I sent a couple emails to myself from my Gmail account and received all of them. Sent the messages from my Yahoo account and still have not received them. I am getting no undeliverable messages in return. I have searched through the IMF Archiver and none of the messages are in there. I have been checking it daily. This has been happening for about 4 or 5 days now. It's hard to say exactly when, as nothing has really changed. I applied SP2 per Microsoft's recommendations last night and the server.