🚀 go-pugleaf

["Followup-To:" header set to comp.os.ms-windows.networking.tcp-ip.]
On Thu, 02 Sep 2004 23:13:58 GMT, Mike Romp <mike.remove@rompnet.net> wrote:
> OS: Windows XP Pro SP1
> NIC: Intel PRO 100 VE
>
> I have a client who has just recently (within the past few weeks) stopped
> being able to send mail through his work email account.  He has a personal
> mail account that works fine.  The mail client is irrelevant as you will
> soon see (OE6).  Both mail accounts are set to use POP3/SMTP.  Both accounts
> use the same server for POP and SMTP (but different from each other).
> Before I go on, I should clarify that by work mail server, I mean the
> account he uses for work email.  It is not on his local network.  He had
> tried XP's system restore before I was even aware of the problem.
>
> I began troubleshooting this problem by having him TELNET to port 25 of his
> work mail server.  The connection times out.  He can connect fine to port
> 110 as he is able to receive mail.  I can connect to his mail server.  He is
> able to connect to port 25 of his personal mail server.  For kicks, I had
> him attempt a connection to port 25 of one of my mail servers (a NETSTAT on
> my server shows nothing while he tries to connect).  Connection times out.
> He can, however, ping my mail server and connect to its web server.  The
> problem has to exist somewhere in or above the TCP layer.  It is not a DNS
> issue as we have tried IPs as well as FQDNs and the hosts file is fine.  A
> NETSTAT on his computer while trying to connect to port 25 gets no further
> than SYN_SENT.

Does his ISP filter port 25 outbound? If it does, use the submission port
(587) with SMTP AUTH.

-- 
-- Skylar Thompson (skylar@os2.dhs.org)
-- http://www.os2.dhs.org/~skylar/