Windows 2000 server telnet connection to mail server

[nichols]

I have an application that e-mails a message via port 25 to users within our Exchange 5.5 NT 4 based e-mail system.

This worked fine until a couple of weeks ago when the process failed and has failed ever since. No known changes have been made to either server.

Now when we try to telnet to port 25 of the mail server from the Windows 2000 server we get the following error message:

Connecting To xxx.xxx.xxx.xxx...Could not open a connection to host on port 25 : C
onnect failed

However when we telnet to port 25 of the same mailserver from a Windows 2003 server the telnet connects.

I have checked that the ip address of the w2k server is allowed as a relay server in the imc connector within Excange and it is. Also the relay service is working from a number of other servers and did once work from the w2k server.

I have also checked that the ip filtering option has not been set on the w2k server.

I am now completely baffled as to what is stopping the telnet.

I hope someone out there can help

cheers


However when we try to telnet to pro

 

[minxca]

Did you upgrade your antivirus recently?

 

[nichols]

Yes we did, we have McAffe VirusScan Enterprise 8.0.0. I have found the problem. It is the virus engine that also has access protection rules. One of the rules is to prevent mass mailing worms and blocks port 25 outbound from the server. When this rule is turned off smtp mail works fine.

Thanks for replying though, feeling a bit stupid that I did not spot this in the first place

Cheers
Nichols