Telnet blocked

[Guest]

I have a WinXP Pro workstation (not on a domain) in a 3-computer peer-to-peer
network that has begun failing to send/receive e-mail (Outlook 2003). Sure
enough, when I manually run telnet to the SMTP/POP servers on ports 25/110,
it simply fails. I can telnet to the mail servers from the other
workstations, so I know it is not my firewall. Windows Firewall is disabled
on all the workstations.

The problem does not appear immediately after the computer is restarted.
E-mail works for a while after a reboot, but then eventually quits working
along with telnet to those ports.

Where do I start diagnosing the cause? Although it smacks a little of a hack
or hijack, I have run HiJackThis, and it turns up nothing unusual. I am
currently setting up a batch file to pipe netstat -o to a text file, but this
will show me only if those ports are in use, not if telnet is being adversely
affected or if/where the ports are being blocked.

 

[Lanwench [MVP - Exchange]]

I have a WinXP Pro workstation (not on a domain) in a 3-computer
peer-to-peer network that has begun failing to send/receive e-mail
(Outlook 2003). Sure enough, when I manually run telnet to the
SMTP/POP servers on ports 25/110, it simply fails. I can telnet to
the mail servers from the other workstations, so I know it is not my
firewall. Windows Firewall is disabled on all the workstations.

The problem does not appear immediately after the computer is
restarted. E-mail works for a while after a reboot, but then
eventually quits working along with telnet to those ports.

Where do I start diagnosing the cause? Although it smacks a little of
a hack or hijack, I have run HiJackThis, and it turns up nothing
unusual. I am currently setting up a batch file to pipe netstat -o to
a text file, but this will show me only if those ports are in use,
not if telnet is being adversely affected or if/where the ports are
being blocked.

The Windows firewall doesn't block outbound traffic, so it wouldn't be that
even if you had it enabled. Do you have any third party antivirus/security
software suite installed? Such as McAfee / Norton? That might be doing it.

 

[Guest]

I have only Norton AV - no Internet Security or anything.

It is curious to me that e-mail functions normally when rebooted but
eventually gets blocked. I don't know how long it takes because the user
doesn't tell me right away. I set up a batch file so the user can run netstat
-o > netstat.txt when it fails and send me the resulting text file. However,
I think this will tell me only if the port has been hijacked, not if/where it
is being blocked.

I suppose it is possible that the problem is with the router, but unlikely,
since telnet on both ports works from other PC's on the LAN even while
failing on this one.