[COFF] OT: Any DKIM People Out There?

[Steffen Nurpmeso]

Steffen Nurpmeso wrote in
 <20250821125304.4zkVMemq at steffen%sdaoden.eu>:
 |Steffen Nurpmeso wrote in
 | <20250821124141.BEJr5YJE at steffen%sdaoden.eu>:
 ||Warren Toomey via COFF wrote in
 || <aKanpE22V+eay62r at minnie.tuhs.org>:
 |||Hi all, I've had a question/issue raised with DKIM on the TUHS/COFF \
 |||mailing
 |||lists from a subscriber. I'm running Mailman3 and I'm a DKIM newbie. They
 |||say:
 | ...
 |||I'd be very happy to have someone/some people review my mailman3, postfix
 |||and rspamd configuration and suggest changes.
 | ...
 ||But.  Mailman3 config is at [1]
 ||
 ||  - Remove (or rename) old DKIM headers [1]: not so important, but
 ||    good.  Because.
 ||      remove_dkim_headers: yes
 |
 |So that seems to be done.

(Within the [mta] configuration section i think this belongs.)

 |  ...
 ||  - Perform the mitigations [2].  Ensure to *always* mitigate and
 ||    change the From: line to those "via" style things.
 |
 |That not.  Please let me try post one message one more time, as
 |i normally filter DKIM etc very heavily, because of all the noise.
 |
 ||      dmarc_mitigate_unconditionally
 ||      dmarc_mitigate_action: munge_from
 ||
 ||  [1] https://docs.mailman3.org/projects/mailman/en/latest/src/mailman/con\
 ||  \
 ||  fig/docs/config.html
 ||  [2] https://docs.mailman3.org/projects/mailman/en/latest/src/mailman/han\
 ||  \
 ||  dlers/docs/dmarc-mitigations.html
 ||
 ||In general it can only be "mitigate, mitigate, mitigate" (think
 ||Ballmers "Developers! Developers! Developers! -- just like that!),
 ||and unconditionally so, because why have all the DNS lookups and
 ||all the noise for nothing, just give anyone the same appearance.
 | ...
 |
 |Sorry for that noise.

Hmm.  Indeed, dear Warren, whereas your message had a DKIM
signature (even two), this one of mine that was returned via COFF
does not have any DKIM signature in it at all?

I think Mailman3 can do anything on its own, the question is how
you do it, via it, via external milters (rspam), and how it all
interacts :-)  Email is too complicated, but you will not move
them a bit, it is very, very sad.
All this could however also be PEBKAC ("Problem Exists Between
Keyboard and Chair") from my side.

But the above are anyway the correct suggestions.
How to do it with Mailman3, with that terrible documentation?
Maybe
  https://docs.mailman3.org/projects/mailman/en/latest/_sources/src/mailman/rules/docs/dmarc-mitigation.rst.txt
helps you a little bit more.

--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)