I have a BSD web server and Exchange server on the same network, and despite days and days of trying to get relaying to work to allow the BSD server to send mail directly to Exchange, instead I decided to send the mail from the BSD server out to the Internet and have it forwarded back in. This worked yesterday, but today it just stopped working and I don't know why. I checked the message tracker, and the messages show up, but they're never delivered, and they're not in the message queue. Is there something special I need to do to allow exchange to basically accept and route everything from a given domain?

Update: Even sending a regular email from the domain that forwards emails, Exchange simply ignores it, it doesn't even bounce back. Sendmail reports that it was successful as well.

So, actually, the problem was the mailboxes I was testing with were also forwards (I didn't set that part up) and so the reason I wasn't receiving anything is because it was forwarding yet again to some place else.