Ryan Malayter wrote:
I really think of this idea as an edge-MTA stop-gap solution for an
organization that wants to protect itself from 2822.from forgery until
Unified-SPF or something better is deployed. Heck, it could be done on a
per-recipient basis, only for those users who require the extra
protection (and probably don't use mailing lists or understand
forwarders anyway).
Why not implement it on a mail server of your own, as a proof of
concept, and see how it goes? Until you try it, you're just speculating
that it won't cause any non-trivial problems.