Valdis(_dot_)Kletnieks(_at_)vt(_dot_)edu writes:
If we're trying to provide advisory eliminate-dups, then a better thing to do
might be to dust off Bernstein's Mail-Followup-To: proposal from http://
cr.yp.to/proto/replyto.html
``Dust off''? A Google search for Mail-Followup-To returns nearly half a
million hits. I see Mail-Followup-To in a large fraction of mailing-list
messages. You're entitled to speculate that IETF action would increase
use of Mail-Followup-To, but you're not entitled to pretend that IETF
action is a prerequisite to widespread use of the protocol.
---D. J. Bernstein, Associate Professor, Department of Mathematics,
Statistics, and Computer Science, University of Illinois at Chicago