To: drums@cs.utk.edu
Subject: Re: Headers and agents
In-Reply-To: <65knI4UEcsB@khms.westfalen.de>
References: <199603272242.RAA23893@wilma.cs.utk.edu> <19960327225504.23010.qmail@koobera.math.uic.edu>
Date: Fri, 29 Mar 1996 12:23:17 +0000
From: Tim Goodwin <tim@pipex.net>
Message-ID: <AABFMzFb1jUAARg3@pipe.pipex.net>

> > > I suppose it wouldn't hurt to say that mail with return-path <> should
> > > not be forwarded to lists.
> >
> > That would be a different type of disaster---bounce messages
> > disappearing without a trace.
> 
> No no no. Nobody said anything about disappearing without a trace.

Consider a message where the originator address is a mailing list.  If
such a message bounces, the proposed rule means that the bounce must
either be rerouted to an administrator address, or dropped.  Yet there
is absolutely no reason why the bounce should not be forwarded to the
list, provided the null return-path is preserved.

It is a mistake at any protocol level to base routing decisions on the
source address.

Of course, messages from <> should not be forwarded to a discussion
list like DRUMS, but <drums@cs.utk.edu> never appears as an originator
address, so such a message could only be created by broken software.
Mailing lists have wider applications than discussion lists.

> >                               The right solution is to say that an
> > envelope sender of <> must not be rewritten.

I concur.

Tim.