[CentOS] Sendmail, mailertable and DNS weirdness.

Wed Jun 21 12:45:19 UTC 2006
Les Mikesell <lesmikesell at gmail.com>

On Wed, 2006-06-21 at 05:23, Will McDonald wrote:

> The MX for one of our domains, blah.com, pointed at an internal
> Exchange server. Mail relayed to a Sendmail MailScanner which then
> delivered to Exchange for this domain. The domain expired leading to
> all its mail queueing in Sendmail. So far so sensible.
> 
> While waiting for the domain to be renewed I setup a mailertable entry
> to bypass DNS and route mail directly to the Exchange server...
> 
> blah.com  smtp:[192.168.10.10]
> 
> I rebuilt mailertable then tried flushing the queue with...
> 
> sendmail -q -v -qRblah
> 
> ... which resulted in a bunch of "Transient parse error -- message
> queued for future delivery" errors due to DNS resolution failure.

I think files in the queue have already saved the final
destination after all lookups in their control files.
If that was a name when the first attempt failed it
will be a name on the retries.  

> I thought mailertable entries bypassed DNS?

I can - or the [name] notation can make it take an
A record first instead of trying for an MX.

>  Does Sendmail cache the
> state of the destination for queued messages somehow? In the
> qf${msgid} files in the spool?

Yes, I think that is your problem.  An entry in
/etc/hosts should have allowed the delivery to complete,
though.

-- 
  Les Mikesell
   lesmikesell at gmail.com