Mortimer wrote:
A customer has a network of several PCs connected to broadband via a router.

All the PCs have worked perfectly until the other day when one (Windows
2000, Outlook Express 6, AVG anti-virus, no software firewall) has stopped
being able to send email, although it can still receive email. The symptom
is that OE times out on the sending, with no actual error code.

The other PCs on the network, configured to use the same POP and SMTP
servers, work fine.

"telnet smtp-server 25" gives no response for him, whereas when I try it I
get a typical sign-on message. Given that the PC has no firewall (not even
the Windows one, since it's W2K, not XP), I'm not sure what could be
blocking the port 25 traffic just for that PC.

Any suggestions?


This can heppen if you have a trojan loaded that has 'borrowed' port 25
for its own purposes (eg: spam mailing) - and AVG may not detect it.

You mightg spo something with tcpview:

http://www.microsoft.com/technet/sys...s/TcpView.mspx

Do some scans

Fire up Internet Explorer and visit http://safety.live.com

Fire up IE or Firefox and visit http://housecall.trendmicro.com/