We have an Watchguard firewall as our internet firewall. We have an Exchange server on the private network. Previously, we just forwarded port 25 from the firewall to the Exchange server. We have added an ISA 2004 server on the DMZ firewall, along with the SMTP server. Configured the Watchguard to send port 25 to the ISA server and allowed port 25 from the ISA server to the internal exchange server. Setup the SMTP virtual connector in Exchange. End result is we can send e-mail out, but cannot receive. I can telnet port 25 on the ISA server, so SMTP is working, but if I try it from the outside or from the internal LAN, no good. (421 - SMTP SERVICE NOT AVAILABLE) I'm pretty certain I have the correct rule on the Watchguard, so I'm thinking ISA firewall is blocking SMTP? I created a rule for it, but perhaps it's wrong (this is my first time using ISa server).
Can anyone offer tips for setting up ISA server to accept SMTP traffic
I created an access rule on the ISA server and now I can telnet to port 25 from the internal network, but it still does not work from the outside. The Watchguard firewall sees the connection attempt, shows that it has routed the traffic to the ISA server, but delivers a connection timed out status. Still looks like there is something not right in the ISA firewall setup. Any ideas, anyone?