[Mailman-Users] Need some help with Mailman and Sendmail

[Virginia Beauregard]

On Tue, 25 Jul 2000, Matt Starnes wrote:

> test: "|/etc/smrsh/wrapper post test"
> test-admin: "|/etc/smrsh/wrapper mailowner test"
> test-request: "|/etc/smrsh/wrapper mailcmd test"
> test-owner:  test-admin
> 
> I have linked /etc/smrsh/wrapper /home/mailman/mail/wrapper

As others have mentioned, this is really the backwards way of doing
things, and will likely confuse other administrators, but is not
inherently a problem.

>    ----- Transcript of session follows -----
> 553 unix.ltlb.com. config error: mail loops back to me (MX problem?)
> 554 <test-request at unix.ltlb.com>... Local configuration error

This is entirely a Sendmail misconfiguration problem.  I noticed your mail
came from @mail.ltlb.com, while this is coming from @unix.ltlb.com.  From
poking around, I notice you only have MX records for your domain
(ltlb.com), not either of these hosts (mail.ltlb.com or unix.ltlb.com).
If you have Sendmail configured to do masquerading properly this may not
be a problem, but it is a good idea to have MX records for all hosts which
mail may appears as addressed from.

Secondly, and this is where I think the problem lies, from what I gather
from this error message and poking around in your DNS, unix.ltlb.com
should connect to mail.ltlb.com to deliver it's mail, correct?  Is
unix.ltlb.com in mail.ltlb.com's /etc/mail/local-host-names?  This is the
Sendmail's replacement (in versions >8.9) for what used to be
/etc/sendmail.cw; it is the list of hosts for whom you can accept mail. If
unix.ltlb.com is not listed here, mail.ltlb.com will not accept mail for
it, at which point it will bounce back to unix.ltlb.com, thus looping as
the error message reports.

In addition, the O'Reilly DNS & BIND book points out another possible
misconfiguration here: you should always use the canonical name of the
host as the MX record.  However, I can't really tell if you are in fact
doing this, because your DNS seems to have just flapped.  :( I also
reasonably sure that you can get around this limitation with
/etc/mail/local-host-names.

I hope these suggestions are helpful.  The rule I always go by when trying
to debug a Sendmail problem is "Have you checked
/etc/mail/local-host-names"?  It's very often the cause of your troubles.

--
Virginia J. Beauregard                            virginia at texterity.com
UNIX Systems and Network Administrator                   Texterity, Inc.