Question : cannot telnet port 25 from webserver

I have a web server with pages that email forms.  I used SMTP to connect to our Exchange server.  This recently stopped working.  On further investigation I found that the web server cannot telnet the exchange server on port 25, I then started the local SMTP server and I could not telnet the localhost on port 25.  I can ping sucessfully.

From my own desktop I can telnet the email server on port 25.  I have disabled all antivirus software and firewalls.

The exchange server is running on Windows Server 2003.  The webserver is Windows 2000 Server SP4 running IIS.

Answer : cannot telnet port 25 from webserver

I tried all the things you mentioned with now success.  I ran Microsoft update and applied a few patches and all seems well again.  Very strange.