(a) Reply-To with some magic address that is valid syntax but a
no-op. maybe this:
Reply-To: nobody :;
But in the case of mailing lists, which is where this requirement
most
often arises, that might also prevent replies being sent to the
mailing list (except in MUAs that had an explicit command for
"Reply-To-List").
not if the list were on the To or CC line and the recipient did a
"reply
to all". (I'm assuming that reply-to: nobody:; would just remove the
addresses obtained from the To and CC fields of the subject message).
Yes, but Reply-To-All is not the way I like to reply to mailing lists
(though it is often the only one that works).
sorry, I think you're stuck with that. there are way too many problems
with lists that mung reply-to. munging from would be even worse. I
suppose you could argue for a UA that in the presence of list-post,
sent replies to that address instead - but I think that would be very
counterintuitive.
Keith