sender/postmaster notifications

[Matt Wilson]

I have a weird problem.  I set up our e-mail server as a test server (with
an IP address and hostname different than what the live server is).
Everything worked fine.  The sender, recipient, and postmasters were
getting messages.  I then moved the server live and now it just blocks
viruses from the recipient, but gives no other notices.  All other e-mail
is being processed fine. I think that somewere I have forgotten a hostname
or something.  Here is a maillog excerpt:

Oct 25 08:02:47 kemron-lab sendmail[736]: g9PBxcpJ000736: to=mwilson at kemron-
lab.com, delay=00:03:09, xdelay=00:03:09, mailer=relay, pri=30137,
relay=localhost.com. [10.20.40.80], dsn=4.0.0, stat=Deferred: Connection
timed out with localhost.com.

I'm not sure about the localhost.com thing.

Thanks