I'm following the wiki on Debian Sarge, and I just got to the part that says 'test everything before proceeding'. I can send out just fine, but when I try to reply to the message, it just disappears.

I just put in a new mail server (RH 7.3, latest Postfix, Bind 9, etc.). I've got multiple IPs on one of the network adaptors, one for mail.domain.com, one for ns1.domain.com, and one as a mnagement IP ...

Unless you're a sysadmin you don't generally have to worry that much about getting email delivered, you just hookup your GUI email client to your external email account and you're done. But what if ...