Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!revell
From: revell@uunet.UU.NET (James R Revell Jr)
Newsgroups: comp.mail.uucp
Subject: Re: rerouting to an absolute address
Message-ID: <100522@uunet.UU.NET>
Date: 9 Aug 90 01:26:31 GMT
References: <1990Aug6.230109.4220@ibmpa> <1990Aug7.081953.6108@terminator.cc.umich.edu> <796@wshb.csms.com>
Organization: UUNET Communications Services, Falls Church, VA
Lines: 39
Bcc: revell

In article <796@wshb.csms.com> michaelb@wshb.csms.com writes:
>I don't get why sgi.com doesn't handle routing to apple.sgi.com.
>I admit to being fairly new in this game. I have three machines
>and none are internet connected. We have one MX record for the company.
>I manage to sort out everything based on what prefixes the domain.

Well, this might be a bit off from the apple.sgi.com discussion, but ..

Remember, domain names are *not* meant to imply any routing.

If may happen that the system that handles sgi.com (192.48.153.1)
has some link to apple.sgi.com.  If this link is the way they want
mail to get to it then the MX record may list sgi.com

But what if there isn't a link, or it isn't the preferred way to go?
sgi.sgi.com is in Mountain View, CA, but stl.sgi.com is in Hazelwood,
MO.  It might be preferable to direct mail right to stl.sgi.com if it
is IP connected.  If not, there might be a local internet host to do
the job.  In either case, there might be a MX record for stl.sgi.com
that points somewhere other than sgi.com

Your domain, CSMS.COM, happens to have all mail forwarding done through
one point, uunet.  This is the simplest way, especially if everything
you've got is on an internal LAN, but it is by far not the only way.

>I can understand that the bang path will be absolutly worthless if someone
>tries to reroute to the last host, in this case 'apple', but WHY doesn't
>the domain handle getting it to the right place? I have spent a LOT of
>my company's time and effort to get this domain stuff working. Am I still
>missing something?

Perhaps.  Many individual IP connected systems in a domain might be
directly reachable and handle their own mail, or they might have it
go through a specific mail gateway.  A lot of times various subdomains
of larger companies go through different hosts.  The more distributed
your systems are the more demanding your mail routing needs might be.
You might want to check out some RFC's (on mail exchanging or BIND).
--
James Revell	uunet postmaster	revell@uunet.uu.net	/8^{~