Sendmail mystery

[Stuart Biggerstaff]

We just moved our mail from a server in our DMZ to a new one which is
internal with some NAT rules.  Mostly everything is working, but we have
some automated e-mail (a couple of web forms, and sending copies of
logs) being sent from two web servers to accounts on the mail server,
and that sort of fails.

The old mail server was providing DNS for things in our DMZ, and we have
moved that to our main web server.  After a lot of editing of
configuration files and changing rules on our firewall, sending mail
from the web servers works, after a fashion.  That is, it queues to be
sent, and when we flush the queue they go.  Maillog shows the messages
deferred because Sendmail was receiving a host name lookup failure--when
accessing the new mail server for DNS.

Our initial configuration used the old mail server for DNS, while the
new one is supposed to use the web server itself.  The only place I have
entered the name or IP of the new mail server is in /etc/hosts and in
the configs for BIND, but nowhere as a name server.

Anyone have a suggestion where to start looking?


Stuart Biggerstaff
Systems Technician
Linda Hall Library of Science Engineering & Technology
5109 Cherry St.
Kansas City, Missouri 64110-2498

Phone:	(816) 926-8748
	(800) 662-1545 x748
FAX:	(816) 926-8790
URL:	www.lindahall.org