I am using Exchange 2003. Incoming and outgoing mail works fine. I am trying to telnet to port 25on the exchange server from a pc in the same domain and same LAN. I receive "Could not open connection to the host, on port 25: Connect failed". Tried solution in KB908864 http://support.microsoft.com/kb/908864/en-us. That did not solve the problem. Pings to IP and FQDN are successful. Any suggestions? Thanks.

Can you try from the local console of an Exchange server? What happens when you do this: TELNET LOCALHOST 25

What anti virus software are you running?I know that mcafee anti virus blocks port 25

This appears is also locked down on my PC ( XP SP2 running mcAfee virusscan enterprise. ). To check whether mcafee is the culprit look in the mcafee AccessProtectionLog.txt for something like 6/29/200710:52:51 AMBlocked by port blocking rule C:\WINDOWS\system32\telnet.exeAnti-virus Standard Protectionrevent mass mailing worms from sending mail<snippedIPaddress>:25