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Path: utzoo!utgpu!water!watmath!clyde!rutgers!husc6!seismo!sundc!hadron!jsdy
From: jsdy@hadron.UUCP
Newsgroups: comp.mail.uucp
Subject: Re: whether to prefix myhost! onto the From: or not..
Message-ID: <525@hadron.UUCP>
Date: Tue, 28-Apr-87 09:24:09 EDT
Article-I.D.: hadron.525
Posted: Tue Apr 28 09:24:09 1987
Date-Received: Wed, 29-Apr-87 06:26:19 EDT
References: <16238@amdcad.AMD.COM> <600@vixie.UUCP> <870@xanth.UUCP> <603@vixie.UUCP>
Reply-To: jsdy@hadron.UUCP (Joseph S. D. Yao)
Organization: Hadron, Inc., Fairfax, VA
Lines: 33
Summary: No absolutes.  Not with relative addressing ...

In article <603@vixie.UUCP> paul@vixie.UUCP (Paul Vixie Esq) writes:
>treating a!b@c as a!c!b pretty tenuous (try nonexistent) -- it's c!a!b.

This time you're wrong, albeit somewhat right.  (*sigh*)

IF you are on a domain machine AND do not have a UUCP connection to
'a', then "a!b@c" goes to 'c', which then must interpret "a!b".

We think, c -> a -> b.  But it could be an odd mail address "a!b".

IF you are not on a domain machine AND have a UUCP connection to 'a',
then "a!b@c" goes to 'a', which then must interpret "b@c".

We think, a -> c -> b.  But it could be an odd mail address "b@c".

IF you are on a domain machine AND have a UUCP connection to 'a',
THEN you are in trouble.  You had better do your best to make sure
that you never get addresses like this; but also just-in-case have
some default rule of thumb which of the above paths you would choose.
(I believe that I generally choose UUCP; but I'm not sure.)

BTW, going strictly by RFC 822, a!b@c is indeed parsed as mail address
"a!b" on machine 'c'.  HOWEVER, that does not mean that there must be
a login or user by that name!  That is merely a mail address, which the
machine may then choose to further interpret.  On Unix machines, it
gets interpreted as a UUCP address, almost inevitably.  On VMS/DECnet,
it seems to mean something else, I can't quite figure out a rational
syntax for what.  This  i s  rather explicitly stated.

	Joe Yao		jsdy@hadron.COM (not yet domainised)
	hadron!jsdy@{seismo.CSS.GOV,dtix.ARPA,decuac.DEC.COM}
{arinc,att,avatar,cos,decuac,dtix,ecogong,kcwc}!hadron!jsdy
     {netex,netxcom,rlgvax,seismo,smsdpg,sundc}!hadron!jsdy