My Win2k SMTP is having a problem delivering email to other domains. Can
anyone explian why my SMTP is attempting to send mail to a web server IP,
and not the proper mail server IP?
When attempting delivery, there is no response to the HELO by the
destination server. I snooped the connection to the internet to see what was
going on, and found that my SMTP is trying to send mail to the destination
domain's web server, not it's mail server.
I then scrolled back to see the DNS query sequence for the remote domain. My
machine sends a single DNS query, and I do get a DNS response with the IP of
the host domain, but no mention of the mail IP (MX record). Then my SMTP
server then uses this host IP in an attempt to send mail, which fails the
connection attempt. Specifically, when sending mail to pacbell.net, I see
the DNS answer back with 18.104.22.168, and then my smtp server attempt to
send mail using that ip, which the connection attaempt fails. When doing a
nslookup on pacbells MX records, I get the correct mail servers for pacbell
(mta1.snfc21.pbi.net = 22.214.171.124 and others). BTW, similar failure mode
happens for all outgoing mail domains, not just pacbell.