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Path: utzoo!mnetor!seismo!honey
From: honey@citi.umich.edu (Peter Honeyman)
Newsgroups: comp.mail.uucp
Subject: Re: Bracketing in mail addresses - NO NO NO NO NO
Message-ID: <43989@beno.seismo.CSS.GOV>
Date: Wed, 17-Jun-87 00:21:00 EDT
Article-I.D.: beno.43989
Posted: Wed Jun 17 00:21:00 1987
Date-Received: Sun, 21-Jun-87 09:27:25 EDT
Sender: rick@seismo.CSS.GOV
Lines: 27

precedence rules for ! and @ are a hopeless miasma that everyone
solves their own way.  here's one way approach: if it's from
uucp, give !  precedence; if it's from smtp, give @ precedence;
discourage locals from using mixed addresses, but if they do, be
consistent.

trouble arises when routing through 822-land.  (uucp has no
trouble with source routing, especially if you use a router.)

here are two examples that illustrate the problem, especially
for internet sites:

	wiscvm.wisc.edu!pucc.bitnet!user

pucc.bitnet!user fails; you must use user@pucc.bitnet, i.e. smtp
has to say MAIL TO:<user%pucc.bitnet@wiscvm.edu> (or, i assume,
MAIL TO:<@wiscvm.wisc.edu:user@pucc.bitnet>).

	sun.com!frame!user

user@frame fails; you must use frame!user, i.e., smtp has to say
MAIL TO:<frame!user@sun.com>.

sun and wiscvm are playing by the same set of rules.  what does
that say about the rules?

	peter