It seems that when I "Hardened" my mail server according to http://www.scalix.com/wiki/index.php?ti ... ixSecurity that the section for changing the SMTP greeting ( http://www.scalix.com/wiki/index.php?ti ... P_greeting ) caused my Outlook to not look at the authentication. Thus I got the 550 messages. Once I removed that section... It started working fine.
I don't know if that's the solution or not. I guess at this point I will cross my fingers and hope. Any other thoughts or ideas?
Thanks,