Using Exchange 2007 - (CAS,Hub,Mail and Transport). I have all external mail coming in on http/s to webmail and outlook anywhere and port 25 smtp (mail.domain.com). Firewall NAT rule is External to Internal.
I then created a DMZ and now have webmail and outlook anywhere http/s going from External>>>>DMZ>>>Internal and it works fine. But when I changed smtp 25 to External>>>DMZ>>>Inside - I cannot receive any emails from external, I can send though.
I Only changed the way it is being routed, instead of going from External (mail.domain.com) to Internal (mail server). I have it going External (mail.domain.com)>>>(DMZ IP) >>>(Internal Mail server).
I didn't change any IPs or URLs or anything on the External or Internal and webmail and outlook anywhere are working fine through the DMZ.
I thought maybe it could be the external mail filter in the cloud that hits our external domain name but since I'm not touching anything external I don't see how that would matter.
Any suggestions? Thanks!
