Re: zmailer no MX record bug??

[Tom Samplonius <tom@uniserve.com>]

On Mon, 25 Sep 1995, Trevor Paquette wrote:

> On Sep 25, 20:17, Trevor Paquette wrote:
> > Subject: zmailer no MX record bug??
> > Ok.. on our internet gateway (running 2.97.. ok ok I know it is old.. but
> this
> > might be happening on 2.99.10 as well) we get a MAIL From: like:

  2.99.10?  That is old too, but more more importantly, bad.

> > MAIL From:<user@crap.com>
> >
> > The mail then goes into the zmailer system and then tries to connect to our
> > mailhost and the From is now: user@crap.com.aec.ca ?????????
> >              Where did this come from????   ^^^^^^
> >
> > HELP! I looked at our routes file, nothing there.. I suspect it is somewhere
> > in the p-smtp.cf file or the like. Has anyone else seen this?
> >
> 
> I forgot to mention that this ONLY happens on addresss that do not have a
> valid MX record..

  You DNS system has:

*.aec.ca.	IN MX 10 mailhost.aec.ca.
		IN MX 20 aecgate.aec.ca.

That is why this is happening.  This entry will only match entries that 
have no other information (ie. no specific MX record).

 Your resolver will take add the default domain (probably "aec.ca") from 
/etc/resolv.conf to _all_ lookups, before resolving.  With the wildcard 
MX recored, that always works.

  Unless you have a good reason for doing so (there are some, but they 
are _very_ few), I would remove the wildcard MX.  Wildcard DNS entries are 
discouraged these days.

  Of course, Zmailer's baviour is bogus for your situation.  It appears 
to be trying to convert the MAIL FROM mailpath to a FQDN.  For example 
convert:
  jsmith@host.department
to:
  jsmith@host.department.myco.com


Tom