Path: utzoo!utgpu!attcan!uunet!husc6!think!ames!hc!hi.unm.edu!kurt
From: kurt@hi.unm.edu (Kurt Zeilenga)
Newsgroups: comp.mail.sendmail
Subject: Re: MX records and gateways
Message-ID: <23625@hi.unm.edu>
Date: 10 Aug 88 16:35:08 GMT
References: <452@umn-d-ub.D.UMN.EDU> <23624@hi.unm.edu> <453@umn-d-ub.D.UMN.EDU>
Reply-To: kurt@hi.unm.edu (Kurt Zeilenga)
Organization: U. of New Mexico, Albuquerque
Lines: 53

In article <453@umn-d-ub.D.UMN.EDU> rhealey@ub.d.umn.edu (Rob Healey) writes:

>	Yes, I know. The trouble is it WON'T try to talk to the
>	exchanger, it wants to talk to the non-networked site. B^(.
>
>	I guess I should clearify. I'll use REAL site names. Say I

Thanks.  I thought you were trying to find reroute hosts that had
MX records.  I am glad to know you are not doing that.

>	want to mail to joe@bungia.mn.org. a.cs.uiuc.edu HAS an MX
>	record for mn.org and thus can be used as a gateway to it.
>	HOW do I tell sendmail it should contact a.cs.uiuc.edu rather
>	than bungia.mn.org. bungia.mn.org is a CORRECT canonical name
>	it just doesn't have an SMTP connection. CAN sendmail find out
>	that a.cs.uiuc.edu is the mail exchanger for bungia.mn.org and, finding
>	that out, can it talk to a.cs.uiuc.edu rather than sending out a connect
>	request to bungia.mn.org, a site that isn't directly on the net.

The SMTP mailer will deal with querying for MX records and delivering
appropriately.  No further sendmail rewriting should be done, the mailer
will take it from here. If the host does have any MX records for it then
it will be delivered to any known IP addresses that can be found.  If no
MXs and no As, then the SMTP mailer will return a host unknown error.  The
SMTP mailer does all this dynamically each time it attempts to deliver the
mail (since status of MX'ers may change).  I know of no good way of
watching it decide the proper MX (does anyone?).

>	Right now, no matter what I try, sendmail wants to talk to the
>	non-networked site, NOT the mail exchanger. How do I get sendmail
>	to talk to the right machine?

Sendmail 5.59 should run properly under named (4.8) and does have MX
support.  You should verify correct installation of named, the libs,
and sendmail.  Did you compile sendmail with "-DMXDOMAIN"?

>	I thank Mr. Zeilenga for his comments and hope that my clearification
>	explains better the question I was asking.

Thanks for the clarification and I hope these comments help.  

>			-Rob Healey
>			rhealey@ub.d.umn.edu