Hello Folks,
I am wanting to Telnet to SMTP port 25 from an external location, meaning an internet location outside of the LAN to test some configurations of my Exchange Server.
My setup is an SBS2003R2 Premium Server (with ISA2004) with all updates current. There are 2 NICs - one for the WAN with an ADSL modem/ router, and another for the LAN.
There is a correctly established MX record that points to the WAN NIC of the server.
SMTP mail is being received without problem through ISA by Exchange using the MX record.
There is a NAT entry on the modem/router that points port 25 to the WAN NIC on the SBS server
When I Telnet from outside of the LAN, nothing is being displayed in ISA's live monitoring. Telnet hangs then reports connection lost.
When I Telnet from a workstation within the LAN to either of the servers NICs, I can connect to Exchange as expected.
What configuration on the modem/router or IAS Server am I missing that is not allowing the same connection from an external computer ? .. or perhaps there is something else that I have not considered.
Any advice or assistance greatly appreciated.
Start Free Trial
