Quoting KatolaZ (katolaz@???):

> I might have missed something, but there is no need to speculate: it's
> sufficient to have a look at the headers of emails posted on DNG. Most
> of them do not have a Reply-To: header set, which means that Mailman
> does not add anything (there is a config option to do that, but it's
> quite annoying TBH).

Bless you for trying to help, Enzo, but I think you've addressed an
entirely different question from the one Hendrik just raised.

Hendrik was hoping that Mailman's DMARC mitigation would not discard a
poster's existing Reply-To: header in cases where Mailman appends one of
its own pointing back to the poster. In reply, I was citing reasons to
expect it will not discard such a header.


As I've already explained, Dng's Mailman configuration has been, since
December 6th, munging the From: header in cases where the poster's
domain has a DMARC policy of p=reject or p=quarantine, and _only_ in
such cases. For your reference, in Mailman v. 2.1.18 and later admin
webUI screens (Dyne.org's current version being 2.1.23), this is on
page Privacy Options, Sender Filters, item 'Action to take when anyone
posts to the list from a domain with a DMARC Reject/Quarantine Policy'
aka dmarc_moderation_action. Applying the mitigation Mailmna's
developers recommend consists of changing default radio button 'Accept'
to "Munge From'.

And then one also changes 'dmarc_quarantine_moderation_action)' to Yes.

Mailman's developers no longer recommend the similar-looking setting
'Replace the From: header address with the list's posting address to
mitigate issues stemming from the original From: domain's DMARC or
similar policies' aka from_is_list on page General Options: Opting for
that (older) version of Mailman's munging kludge unconditionally
applies it to all postings whether they are from DMARC-encumbered
domains or not.

You may or may not recall that we discussed all of these matters on
Devuan-dev in a couple of threads starting October 29th. It took until
December 6th for action to be taken, but we went through the matter a
few times in discusison.