Crystal Kolipe via Mutt-dev wrote in
 <[email protected]>:
 |On Sat, Feb 14, 2026 at 11:35:03AM +0800, Kevin J. McCarthy wrote:
 |> Now that we're back to applying patches from the mailing list, I have a
 |> question about technique.
 |> 
 |> The Mutt mailing lists have "dmarc_moderation_action" set to "Munge \
 |> From",
 |> which means when a sender's domain has a DMARC Reject/Quarantine \
 |> Policy set,
 |> the mailing list rewrites the From address.
 |> 
 |> Without this, a fair number of receivers bounce the message, which \
 |> ends up
 |> unsubscribing them eventually.
 |
 |If the senders are including valid DKIM headers, and the MX of the \
 |subscribers
 |is capable of verifying them, then the messages should pass DMARC Reject.
 |
 |So maybe only rewrite the From address if the sender doesn't sign the \
 |original
 |message?  And of course, don't strip the DKIM headers from the original \
 |post
 |when not re-writing.

To remark that there are people that sign List-* headers, even though
they shouldn't (IETF art director of time saying in [1] (said headers)
  If Jim's server is signing List-* fields for a message that hasn't gotten
  to a list yet, that seems like it guarantees this message will have DKIM
  problems.
) but i do not think it is forbidden either.  Nor do i think it
should etc etc etc.

Anyhow posters can cause verifier hiccups unless the used
mailing-list software is smart enough for "graceful" decisions,
which mailman2 definetely is not (no idea of mm3).  (An iterated
DKIM could overcome that, and, dreaming, drop all stuff back to
the 90s except for unfortunately 2047 (2231 i like), but, whether
IETF email will happen; maybe as a hypothetic jmail, perhaps.)

(And to add that i personally made my peace with "mitigate
anything" (aka munge), because i think all that horrific IETF
email stuff dmarc/arc/"darn"/spf/you name it will never be the
right thing; i vote(d) for Wheeler's ~"any problem is solved with
an extra indirection", and that would mean here an iterated DKIM
that would allow user software like mutt to restore original
(verified) content, so then automated is this, and users see
that.  Just my one cent.)

  [1] 
https://mailarchive.ietf.org/arch/msg/ietf-dkim/G1xEBo7UQ9f9AAwuRnbt7e7Frms

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)

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