I have users that want to access GW with different clients than the GW
client (smart phone, Thunderbird etc). They can POP the email from the
server to their client, but cannot send.

In troubleshooting, I'm trying to telent to port 25 on the public IP
address of the server, but am getting 'connection failed'. I can telnet
to the private IP address from inside the firewall.

As part of the troubleshooting, I put a rule to allow any traffic to the
server, and I still can't telnet to 25, so I don't think it is a
firewall problem.

I *can* send email from my gmail account to me@server.domain.com.

The server is GW 8.02, on NW 6.5 sp8.

What could be stopping the sending of email and the telnet to port 25
from outside the firewall?