Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!shadooby!accuvax.nwu.edu!nucsrl!gore
From: gore@eecs.nwu.edu (Jacob Gore)
Newsgroups: comp.mail.uucp
Subject: Re: circuitous return paths
Message-ID: <3400011@eecs.nwu.edu>
Date: 3 Apr 89 05:50:48 GMT
References: <123@s5000.UUCP>
Organization: Northwestern U, Evanston IL, USA
Lines: 50

/ comp.mail.uucp / alan@s5000.UUCP (Al Kiecker) / Mar 31, 1989 /
|when the destination site does a reply,
|it does NOT take the same path back to us that it took to him.
|I.e, instead of the relatively short path via uunet, it takes the
|longer Internet path as a result of his mailer using our domain address.

|It seems that our problem is that sp.unisys.com is a domain address
|residing in the Internet while s5000.sp.unisys.com is site residing 
|in the UUCP world.

Well, here's what the Internet nameservers say about these addresses:

gore 2> nslookup
Default Server:  gamma.eecs.nwu.edu
Address:  0.0.0.0

> set type=mx
> sp.unisys.com
Server:  gamma.eecs.nwu.edu
Address:  0.0.0.0

Non-authoritative answer:
sp.unisys.com	preference = 10, mail exchanger = relay.cs.net
Authoritative answers can be found from:
relay.cs.net	inet address = 192.31.103.4
PRC-GW.PRC.UNISYS.COM	inet address = 10.5.0.96
KRONOS.NISD.CAM.UNISYS.COM	inet address = 128.170.2.8
> s5000.sp.unisys.com
Server:  gamma.eecs.nwu.edu
Address:  0.0.0.0

Non-authoritative answer:
s5000.sp.unisys.com	preference = 10, mail exchanger = relay.cs.net
Authoritative answers can be found from:
relay.cs.net	inet address = 192.31.103.4
PRC-GW.PRC.UNISYS.COM	inet address = 10.5.0.96
KRONOS.NISD.CAM.UNISYS.COM	inet address = 128.170.2.8
> gore 2> 

So, mail to you goes through relay.cs.net, right?

|What to do?

If uunet is supposed to forward internet mail for you, it should be listed
in an MX record in your domain's nameserver.  If you prefer that uunet is
used rather than relay.cs.net, it should have a "preference" less than 10
(0 is highest preference).

Jacob Gore				Gore@EECS.NWU.Edu
Northwestern Univ., EECS Dept.		{oddjob,chinet,att}!nucsrl!gore