Time for a reality check.
BSD Mail supports two response functions:
1. ``reply to originator'' = From.
2. ``send mail to sender and all recipients'' = From + To + Cc.
Elm supports two response functions:
1. ``reply'' = From.
2. ``group reply'' = From + To + Cc.
Pine supports one function but asks ``reply to all recipients?'':
1. ``no'' = From.
2. ``yes'' = From + To + Cc.
Mutt supports two response functions:
1. ``reply'' = From.
2. ``reply to all recipients'' = From + To + Cc.
Does Keith see the pattern yet? Or shall I start listing non-UNIX
mailers too?
There's certainly no standardization at the edges of these functions.
For example, some MUAs copy the original To into the new Cc field; some
copy it into the new To field.
But there's always a reply function, using From in the common case, and
a followup function, using From + To + Cc in the common case.
Now, once again, here's the problem:
A subscriber sends a message to a mailing list. Someone follows up.
The response is sent to both the subscriber and the mailing list.
As I've already discussed in detail, the extra address is generally
harmful. I don't think there's any dispute about this.
Unfortunately, the person following up can't tell that situation apart
from the following situation, where the extra address is generally
beneficial:
A non-subscriber sends a message to a mailing list. Someone follows
up. The response is sent to the non-subscriber and the mailing list.
So the original author has to put some extra information into his header
to differentiate the two situations.
The obvious solution is a followup field. This would put control
directly in the hands of the original author, and it would be trivial to
implement. My question is what this field should be called.
But you haven't demonstrated that followups are (a) significantly
distinct from replies and (b) worth having.
Existing MUAs support followups. Followups have vastly different effects
from replies. I really don't care whether Keith accepts these facts; his
willful ignorance is not typical of MUA implementors.
And if I equate your word "followup" to my UA's "reply-to-all" command,
the author of the subject message does have the ability to override
the default recipient list of "reply-to-all", using reply-to.
I realize that many UAs don't handle "reply-to-all" this way,
That's because they're following RFC 822, section 4.4.4.
And you completely ignore my argument against unnecessary complexity,
I agree with Keith that RFC 822 is unnecessarily complex. But we're
stuck with it. Keith's proposed change in semantics would be a disaster.
Okay, but whatever that operation is, it doesn't recognize a
followup-to header, and we're better off without one. If someone
modified Berekeley Mail to support a followup-to header, I'd end up
manually editing headers even more often than I do now.
Let's see some specific examples supporting this claim. In exactly what
situation would a followup field, implemented as I described, produce
worse results than the current defaults?
Followup-to won't fix this: for the forseeable future UAs won't
either recognize it or generate it.
Duh.
There's no transition problem here. MUAs can support a followup field
without trouble. As support spreads, duplicate messages will disappear.
---Dan
Let your users manage their own mailing lists. http://pobox.com/~djb/qmail.html