I have a setup similar to this :
Smart host (Exchange Server 5.5) recieving mail at DOMAIN.COM
Linux Box (SUSE with Sendmail) recieving mail at THIS.DOMAIN.COM
Everything is working great except that if I sent a message to email@example.com
for example the failure gets returned to the admin/postmaster on the Exchange server... It doens't get returned to my linux box and then to the user that sent the message.
I have a 2nd setup with Postfix and if I mail the exact same address mail.test.testing.com it gets returned right to the workstation with no problems. I'm not masquerading the envelope only the sender address in sendmail. Anyone have any ideas how to correct that?
BTW I would just use PostFix which is kinda what I want to do but I can't get postfix to masquerade ONLY outgoing mail... I'm trying to see if I can run 2 instances of Postfix and pass it off to the 2nd copy for delivery and that way the masquerading will work so if you can help me on this question also that would also solve my issues.