Newsgroups: comp.mail.sendmail
Path: utzoo!utgpu!jarvis.csri.toronto.edu!neat.ai.toronto.edu!rayan
From: rayan@ai.toronto.edu (Rayan Zachariassen)
Subject: Re: sendmail parsing questions - my comments
Message-ID: <89May11.183003edt.11589@neat.ai.toronto.edu>
Organization: Department of Computer Science, University of Toronto
References: <1635@ur-cc.UUCP> <53257@uunet.UU.NET>  <oYImy1y00VsL80WYtI@andrew.cmu.edu> <6916@bsu-cs.bsu.edu>
Date: Thu, 11 May 89 18:29:50 EDT

In article <882@utkcs2.cs.utk.edu> moore@cygnusx1.cs.utk.edu (Keith Moore) writes:
# It appears
# that the RFC's only require that the _first_ of the "@host" names in
# a route-addr be registered.

Actually the requirement is for all of the RHS's of @'s to be official
canonical for-real Internet domain names.  For various reasons this is
problematic and the proposed solution (in a future draft of the hosts
requirement RFC) will be to deprecate the @: routes in favour of %@ routes.
The stuff between the % and @ then does not have to be in the DNS, as
long as the stuff to the RHS of the @ *is*.  No change in semantics, but
% becomes official.

# Am I missing something here?  It seems like the source-routing mechanism
# is well-designed and tailor-made for sending mail across gateways into
# other mail systems, but isn't being widely used because (a) many mailers
# still do not support source routing even eight years after the RFCs
# were issued, and (b) the RFCs do not make it absolutely clear that such 
# use of source routing is appropriate.

You have the exact right idea in my opinion, problem is that few others
have done it this way.  I've tried to lobby for universal agreement on
some syntax for representing non-Internet routes in the Internet.  If the
%@ proposal goes through, it would be an opportunity for all the gateways
to do it right:

	a!b!c -> c%b@a.dom
	a::"b!c" -> c%b@a.dom
	a!@b:c@d -> !@#$&*@(^%

no more mixed-syntax addresses, please...

fat chance.

rayan


