Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!usc!samsung!interlan.InterLan.COM!interlan.interlan.com!towfiq
From: towfiq@interlan.Interlan.COM (Mark Towfigh)
Newsgroups: comp.mail.sendmail
Subject: Re: Mail addresses and RFC1123
Message-ID: <TOWFIQ.90Jul12154146@interlan.Interlan.COM>
Date: 12 Jul 90 19:41:45 GMT
References: <9007111604.AA29811@cs.niu.edu>
Organization: Racal InterLan, Inc., Boxborough, MA (1-800-LAN-TALK)
Lines: 57
In-reply-to: rickert@CS.NIU.EDU's message of 11 Jul 90 16:04:14 GMT

In article <9007111604.AA29811@cs.niu.edu> rickert@CS.NIU.EDU (Neil
Rickert) writes:

    Now, let's see if I have it straight.

OK.....

   As I interpret RFC1123, a host which does not understand the '!' character,
   but which needs a route for delivery, should not use the address
			     @a:c!u@b
   with its clear interpretation of delivery -> a -> b ->c -> u  but the host
   should instead format the address as
			     c!u%b@a
   with a suggested interpretation of -> a -> c -> b -> u.  (Note that since
   the host does not understand !, it treats 'c!u' as merely a single mailbox
   name).

Where do you get this interpretation?  It seems to me that the two
forms are identical, and should both result in a->b->c->u.  To quote
from the RFC in question:

	It is suggested that "%" have lower precedence
	than any other routing operator (e.g., "!") hidden in the
	local-part; for example, "a!b%c" would be interpreted as
	"(a!b)%c".

    According to my understanding of RFC1123, if my mailer sees the address
      user%mcdchg%clout@gargoyle.uchicago.edu
   it may not touch the local part,

True.

   and must forward the mail to gargoyle, even though experience tells
   me the mail will bounce.  My mailer must not under any circumstances
   reformat the address as
      clout!mcdchg!user@gargoyle.uchicago.edu

True again.

   although with this address the mail would probably be correctly delivered.

WHY?  What is the difference between the way these two addresses are
handled?  Why would one work, and not the other?  If they really do
yield different results, then gargoyle is broken, and you should not
rewrite to support their brain-deadedness -- bounced mail is a good
incentive to fix broken mailers.

   Boy, I am sure glad to have read RFC1123.  Before reading it I was greatly
   confused.  I used to think that the whole purpose was to ensure correct and
   efficient delivery of the mail.

It is -- I think you may have misinterpreted some of the sections.
--
Mark Towfigh, Racal InterLan, Inc.                 towfiq@interlan.Interlan.COM
W: (508) 263-9929 H: (617) 488-2818                       uunet!interlan!towfiq

  "The Earth is but One Country, and Mankind its Citizens" -- Baha'u'llah