I seem to recall that you are slowly drifting towards a new
release, and as i was thrilled by RFC 9057 i thought i bring it to
your attention, in case you are not yet aware. I implemented it
for my mailer right away yesterday afternoon (i have not restarted
it yet though), as i think it good stuff that brings the email
protocol back into good shape, after it has been messed for DMARC
or whatever, resulting in all this terribe "x via y" From: lines,
and the misuse of Reply-To: etc etc.
I THINK ... we can basically implement this via changing the mh-format
templates?
--Ken