This has been an issue for quite a while. It happened with Exchange 2003 and it is not happening with their new Exchange 2007.
All of a sudden reports they receive were not coming through. They come from one address...the IT guy on the senders end informed me they use Sendmail and we were the only clients having this problem. On my end this is the only person we are having problems with. When he tries to send a test email he receives the following log:
Nov 4 17:21:57 devcomm001 sendmail[14217]: nA4HJR42014213: to=<test@domain.com>, ctladdr=<jtest@domain.com>
(502/502), delay=00:02:20, xdelay=00:02:20, mailer=esmtp, pri=120339, relay=mx1.youngmcqueen.com
. [96.235.81.207], dsn=4.0.0, stat=Deferred: Connection timed out with mx1.mydomain.com.
On my end I do not see anything from the sender in Exchange or our Sonicwall email seucirty.
As you can tell I edited the actual email/domains from the above log.
I am currently running a SMTP log on my end, but I do not think anything is going to show up from this sender. At this point any suggestions will great greatly appreciated.