Quoting KatolaZ (katolaz@???):

> I would probably wait for a couple more reports before going down
> munging the "from" header for any message passing through the
> list? That would be *quite* annoying.

I certainly would also, in your shoes, wait to ensure that this is a
real problem before taking action. (I've already seen this matter
affect mailing lists elswhere, but it's obviously appropriate for Devuan
Project to make its own determinations.) I predict that the project
_will_ have to deal with this eventually, in any event, so please keep
what I said around for when you do. ;->

To clarify, though: The configuration I described does _not_
munge the From: header (and append a somewhat compensating Reply-To
header on all mail transiting the mailing list. It does so only
on mail from the specific domains whos DMARC policies make that step
necessary. This is what is being referred to by the Mailman help
text I quoted about setting dmarc_moderation_action, where it would...

     apply to messages From: domains with DMARC p=quarantine 
     as well as p=reject

That's certainly not all postings, just some. (E.g., postings from my
linuxmafia.com domain wouldn't be thus processed, because I don't
implement DMARC at all for my domains, only SPF.)

While you-plural consider this matter, I suggest keeping an eye on
bounce scores in the admin webUI subscriber pages. If there are
subscribers who keep generating high bounce scores, what do the
var/lib/mailman/logs/bounce entries say?

(As someone who spent decades with a well-known Q}FAQ reiterating the
case against munging, I feel decidedly odd endorsing a Mailman wkludge
to mitigate the baleful effects of DMARC as a least-bad remedy, one that
relies on munging, but that's indeed where I've ended up.)