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From: Jacob_Palme_QZ%QZCOM.MAILNET@MIT-MULTICS.ARPA
Newsgroups: net.mail.headers
Subject: Re: Subject: Ambiguity with the REPLY-TO field
Message-ID: <11583@brl-tgr.ARPA>
Date: Mon, 15-Jul-85 12:20:49 EDT
Article-I.D.: brl-tgr.11583
Posted: Mon Jul 15 12:20:49 1985
Date-Received: Wed, 17-Jul-85 21:12:22 EDT
Sender: news@brl-tgr.ARPA
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> FROM: Rich Wales 

> My understanding of the semantics of the REPLY-TO field is that, if it
> is present, it is to be used as a substitute for the FROM field when
> composing replies to the message.

A message system which has two reply commands, called "personal
reply" and "group reply", would for a message without any REPLY-TO
field use the "FROM" field when the "personal reply" is used, and
would perhaps combine the "FROM", "TO", "CC" and "SENDER" fields
when the "group reply" command is used.

Thus if, as you say, the "REPLY-TO" field is to be used as a
replacement for the "FROM" field, this seems to indicate that
maybe the "REPLY-TO" field is mostly to be used for "personal
reply" commands.

However, the text in RFC822, which says that "REPLY-TO" can be
used when you want answers to be sent to a group, seems to
indicate that the "REPLY-TO" field is to be used also for "group
reply" uses.

> FROM: Rich Wales 

> I am not 100% sure I understood your description of the criteria used by
> COM in deciding whether to include the sender in the REPLY-TO field.

An example: Suppose we have a mailing list called III@JJJ with
three members:
- AAA@BBB
- CCC@DDD
- EEE@FFF

Suppose a message written by GGG@HHH, who is not a member of the
list, is sent to this mailing list. Then I would make the
following REPLY-TO clause:
REPLY-TO: III@JJJ, GGG@HHH
This would ensure that GGG@HHH would get the replies, even though
GGG@HHH is not a member of the list.

If however, AAA@BBB sends a message to the list, I would create
the following REPLY-TO clause:
REPLY-TO: III@JJJ
AAA@BBB would *not* be included in the REPLY-TO clause, since
AAA@BBB is a member of the mailing list, and will receive the
message via the list. If in this case AAA@BBB was included in the
REPLY-TO clause, AAA@BBB might get two copies of the replies, one
directly and one via the list (an intelligent system might be able
to merge the two copies before displaying them to the user, but
still the two copies would increase transmission cost and would
confuse COM, since COM would not know whether to regard it as a
personal message or a mailing list message - COM allows users to
give different priority to incoming messages belonging to
different mailing lists.