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From: dhesi@bsu-cs.UUCP
Newsgroups: comp.mail.misc
Subject: Precedence in network mail addresses
Message-ID: <588@bsu-cs.UUCP>
Date: Mon, 11-May-87 14:44:09 EDT
Article-I.D.: bsu-cs.588
Posted: Mon May 11 14:44:09 1987
Date-Received: Thu, 14-May-87 00:39:02 EDT
Organization: CS Dept, Ball St U, Muncie, Indiana
Lines: 24
Keywords: RFC822 address path mail header

I have seen articles complaining about the problems caused by mixed
addressing.  For example, "a!b!c@d.e!f" can be taken as equivalent to
"(c@d.e)!(f)!(a!b!c)" or "(e!f)!(c@d.e)!(a!b!c)".  Many other ambiguous 
combinations of addresses can be invented.

The solution is trivial though it would need a change in most
software.  Introduce symbols that allow you to group address
components.  I have used parentheses above, but they are already
taken.  Perhaps square brackets could be used.  Any machine can then
safely add its own address to the path, thus converting
     any_path
to:
     [myname!any_path]
The next machine can then add its own name thus:
     [[myname!any_path]@next]

So long as each change is accompanied by a new pair of brackets around
the entire result, there will never be any confusion.  The mail
software can also strip out redundant brackets, but their presence
will do no harm.
-- 
Rahul Dhesi
ARPA:  bsu-cs!dhesi@iuvax.cs.indiana.edu
UUCP:  {ihnp4,seismo}!{iuvax,pur-ee}!bsu-cs!dhesi