I do not understand how use of Followup-To in mail would cause any havoc
in Netnews. You will have to explain this havoc to me.
My intention is ***not*** to propose a new use of Followup-To in mail,
but to use it in mail in the same way as it is already used in Netnews.
I.e. if you send a message to two mailing lists, you can use Followup-To
to direct comments on it to only one of the lists. Also, using Followup-To
is a way of saying that you are yourself a member of the list, and need
not get any replies as personal mail direct from the author to you.
In Usenet, the `Followup-To:' field may contain one or more newsgroup
names, or the special keyword `poster'.
Under your proposal (unless I've misunderstood it), `Followup-To:' in
mail would contain mail addresses.
The overall effect may be similar, but the syntax and implementation
details are quite different.
(In fact, I would like to merge the functionalities of Netnews and mailing
lists into one composite service.
This (which I consider a worthwhile, but likely unattainable, goal) must
happen *before* you can start using `Followup-To:' in mail messages. In
particular, you will first have to define a unified naming scheme.