To: Jacob Palme <jpalme@dsv.su.se>
Cc: ietf-drums <drums@cs.utk.edu>
Subject: Re: Clarify amibuities 
In-Reply-To: Your message of "Wed, 06 Dec 1995 14:33:07 BST."
             <Pine.SUN.3.91.951206142804.29273A-100000@ester.dsv.su.se> 
Date: Thu, 07 Dec 1995 08:03:24 +1100
Message-Id: <4426.818283804@munnari.OZ.AU>
From: Robert Elz <kre@munnari.oz.au>


    I guess everyone agrees after the discussion we have
    had, that reply-to is ambiguous. And to resolve this
    by just saying that "reply-to gives the e-mail address
    to which the sender wants replies to be sent" does *not*
    remove that ambiguity.

Yes it does.

I think your problem might be, and correct me if I am
wrong, is that this leaves the sender with a choice, he
might not always want to specify one address for all
replies.   This is not an ambiguity, it is perhaps a
defeciency in the protocol, and may require something new
to fix - it is not however ambiguous.

The sender says "send your replies to *exactly* these addresses",
then, if you choose to honour the sender's wishes, you use Reply-To,
and only Reply-To to generate the reply.  (If you don't want to
comply, anything goes, that is for the recipient to decide).

Now the sender may have a hard time constructing the list of
addresses for his message that will be useful this way, he may
not even be able to, and may have to add text in the message
to express his overall desires (currently), that may take new
functionality to fix.   But that is OK, at least it is better
than now where senders who know exactly where they want all replies
to be sent have no option, apart from possibly sending the header

	From: <where I want replies>
	to: group:;

and no other addressing headers ata ll, then there is only
one useable address in the headers, and so only one thing that
the recipient's UA can choose to use by default.  Of course,
this then limits the choices of the recipient (human) as they have
no idea where the message has really been sent (again, unless it
is in the body).

Let's just do as Keith summarised on the list a month or more
ago.   As a first step in getting things working better, and
as a step in removing an ambiguity, it is a fine solution.

kre