Messages stuck
We have had an issue with our outgoing SMTP email (sent to multiple
recipients) getting stuck in queues since the first week of April when there
were absolutely no changes made to our servers, infrastructure, firewalls,
ISPs, etc. I am lost as a goose and even spent $5k on a brand new server to
take care of it and it does the exact same thing with only Windows Server 2k3
and Exchange 2k3 plus all the updates on it.
Only messages being sent to a group of five to ten or more recipients is
getting held up, everything else goes immediately! The queues that are being
held up...usually until the middle of the night... all have the same message
"The remote server did not respond to a connection attempt." In particular,
we are a mortgage company that sends rates to our correspondents via a PDF
attachment every morning at or around 10:00. There are probably about
150-200 recipients in different domains. About half of the emails are
delivered immediately while the other half will sit there until the middle of
the night when they finally disappear from the queue... not sure if they ever
get delivered. One day abc123.com will get stuck, the next day abc123.com
will be one of the domains that sends immediately.
I have used NSLOOKUP on every domain that gets hung up, and I have used
telnet x.x.x 25 successfully from our email server on every domain while mail
was sitting in the queue. If I FORCE CONNECTION one at a time, the email
goes through immediately! If I try to FORCE CONNECTION on a group at one
time, they immediately go back to RETRY! I have logged, tracked, everything
and nothing shows up! The tracking will show that the email is delivered to
some recipients or some domains, but the others have no tracking info.
I have two ISPs with T1 connections on both and have had everything setup
for email service on both (reverse DNS, etc.). I have our old server using
one ISP/firewall and the new server using another ISP/firewall. The new
server is a totally clean install--nothing extra--while the old server has
Trend Micro scanmail on it.
Any suggestions? Is there ANY WAY possible that a security patch released
around March-April could cause this effect? This is weird beyond logic!! I
have tried all of the logical answers and they don't work so I must be
missing something! I have had our ISP look at it we got around it some this
week by using their server as a smarthost, but I don't want to do that if I
can find a solution because I can't track messages beyond my server.
date: Tue, 23 May 2006 15:10:03 -0700
author: D Wilhelm
