I have a problem when publishing my mail server in DMZ. I've already tested by using telnet [public ip of spam filter] 25 and 110 from outside. It is done successfully. But, when I checked into my spam filter message log, no message received from outside. My spam filter act as mail relay agent and located in DMZ. When I fail to use ASA, I switch back to Linux Firewall and I got no problem. Please help me to solve this.
I have this problem too.