My POP3 Server rule stopped working on ISA 2004 connecting to Exchange Server 2003
Posted on 2008-10-30
I recently switched ISP's and consequently got new IP addresses so during the overlap period I built a new ISA2004 machine to replace my existing one (configuring the new one with the new IP addresses) and when cutover to the new service everything worked.
Now, suddenly, my POP3 Server rule fails to allow Outlook Express clients on the outside to connect to the inside mail server. The error in outlook express is "unexpectedly terminated the connection" and on the ISA server, in logging, I see a connection made and then closed right away.