I have a Server 2003 R2 (fresh install) Exchange 2003 Enterprise and ISA 2004. However I cannot connect to the SMTP server from an external connection. If I telnet localhost 25 no problem but if I telnet the external ip address from another external address the server connects and then immediately drops the connection with connection to host lost.
I'm sure it is something to do with the ISA server but I don't know what.
Any suggestions welcome.