On 7/10/97 at 1:32 AM -0500, Keith Moore wrote:
I thought about proposing a header of the form
Dont-Reply-To: <x(_at_)foo(_dot_)com> if-replying-to <y(_at_)bar(_dot_)com>
which essentially says: if you're sending a reply which would
otherwise be addressed to both X(_at_)foo(_dot_)com and address
x(_at_)foo(_dot_)com out of the recipient list of that reply.
I actually like this idea a bit better than a Followup-To field. It seems
to me that Dont-Reply-To would be a bit easier to automate. We're talking
about putting a feature into our mailer which keeps track of mailing lists
to which the user is subscribed. With a Dont-Reply-To field, we could
generate one of those if any of the recipients of the message were in the
list of subscribed mailing lists. With the Followup-To, it's almost
certainly going to have to be hand-edited by the sender: If the user
replies to a message that *doesn't* have this header and there are some
recipients who don't belong to the mailing list, it's not clear to me how
to figure out whether or not it is a good thing to copy them into the
Followup-To field or not. With Dont-Reply-To, you're giving explicit
instruction to the remote mailer about what to do with a reply-to-all
command. It just seems a little cleaner.
It clearly doesn't have the fine-grained control to be able to redirect the
thread to somewhere else, but I get the feeling that the more likely reason
to use any of these headers is to say "don't send an extra copy to me".
- It does require the sender's UA to be smart about when to add the
Dont-reply-to header on outgoing mail.
It could always be added by hand, but it makes it somewhat easier to add in
an automated fashion.
- It opens the possibility of loops: what does a UA do if it sees
Dont-reply-to: <x> if-replying-to <y>
Dont-reply-to: <y> if-replying-to <z>
Dont-reply-to: <z> if-replying-to <x>
In this case, it's safe to ignore all of the headers.
(*Shrug*) People can generate crappy headers all the time that screw up
remote UAs. I know what a reasonable one of these is supposed to do.
- There's nothing to stop lists from munging this header. Some
lists might want to be "smart" and add Dont-Reply-To headers for
any message sent from a list member. Some people would like this,
since they'd get the benefits of Dont-Reply-To without having
to change their UA. Some people (like me) wouldn't want the list
to add such a header.
I think this is less of a concern. Unlike current Reply-To munging, where
the purpose is to be "helpful" to get discussion on the list, this header
is "helpful" in the opposite direction. I'm not convinced list-admins are
going to be as motivated to do this.
- It doesn't solve the two-list problem
Neither does any other solution as far as I can tell.
Personally, I don't think it's worth it: there's not enough to be
gained for the trouble, and duplicate suppression is more effective
(solves the problem in more cases) and easier to deploy (only requires
support for the recipient who wants to suppress multiple messages, and
that recipient reaps the reward for his own effort). If more UAs had
duplicate suppression there would be very minimal additional gain to
be had from Dont-Reply-To or similar proposals.
I don't think it's a bad idea, actually. Duplicate suppression is fine, but
you still have to spend the time and resources receiving the duplicate
messages. This way, the duplicate never even gets sent.
I think it's worth thinking about.
Pete Resnick <mailto:presnick(_at_)qualcomm(_dot_)com>
Work: (217)337-6377 / Fax: (217)337-1980