Path: utzoo!attcan!uunet!cs.utexas.edu!swrinde!ucsd!ucbvax!TRANSARC.COM!Craig_Everhart
From: Craig_Everhart@TRANSARC.COM
Newsgroups: comp.mail.misc
Subject: Re: user's aliases on the To: line (was: UUnet and munging headers.)
Message-ID: <0aPcFnT0BwwOQrNqA0@transarc.com>
Date: 7 Jun 90 16:44:35 GMT
References: <136802@sun.Eng.Sun.COM>
Sender: daemon@ucbvax.BERKELEY.EDU
Lines: 36

> Excerpts from netnews.comp.mail.misc: 7-Jun-90 user's aliases on the To:
> l.. Dan Heller@turnpike.Eng. (884)

> Sometimes people send mail to an entire list of people with the
> intent that the recipients should *not* be able to reply to everyone,
> just the original author.  This is accomplished by having the user's
> alias name on the To: line and have that passed to the MTA.

The only mechanism (that I know of) that RFC822 provides to allow
somebody to ``hide'' a list of destination addresses is to rewrite the
list as an empty group name.  Thus, you might have some destination list
	To: foobar-list
that could be rewritten before transmission as:
	To: Foobar-List:;
instead of, say,
	To: Foobar-List: name1@host1, name2@host2, name3@host3;
or whatever.

In AMS's delivery system, the obvious way to keep people from seeing the
list of destination addressees, if you really want to do that, is to
mail through a distribution list and then delete or rename the
distribution list.  Thus, once mail has gone out to:
	To: +dist+/afs/andrew.cmu.edu/usr13/cfe/party.dl@andrew.cmu.edu
all I have to do is delete the ~/party.dl file before any of the
recipients gets to see it.

Yes, all these hacks allow To: and CC: fields to be unreplyable in some
special circumstances, but that's not the usual way to operate. 
Furthermore, in these contexts, message recipients have some clue that
the To: list shouldn't be usable.  I don't know if Mush's ``no_expand''
variable leaves such traces.

My own opinions about mail gateways that make no effort to make To:/CC:
fields usable are rather different.

		Craig