[Mailman-Users] DMARC message wrapping not working

[Matthew Pounsett]

I've got a mailman 2.1.26 install I've taken over.  I've attempted to turn
on DMARC message wrapping by setting DEFAULT_DMARC_MODERATION_ACTION in my
mm_cfg.py file, but it doesn't seem to have had the desired effect.  I'm
still seeing messages from p=reject domains going out with their original
headers, and subscribers being blocked as a result of the bounces.

These are the (non-comment) contents of my mm_cfg.py, with the mail domain
anonymized:

from Defaults import *
DEFAULT_URL_HOST = 'lists.example.com'
VIRTUAL_HOSTS.clear()
add_virtualhost('lists.example.com', 'lists.example.com')
DEFAULT_URL_PATTERN = 'https://%s/mailman/'
DEFAULT_DMARC_MODERATION_ACTION = 2

The docs say this sets a minimum bar for the per-list configurations, but
when I go to look at those they're all still set to 0/Accept, and in the
web UI the full range of options is still available.

There is a distinct possibility I've got my hands on the wrong config
file.  This install isn't using the version from the system package
manager.. it's a manually compiled install that looks like it has an
install prefix of /usr/local/mailman.  This file is
/usr/local/mailman/Mailman/mm_cfg.py.  I don't see an obvious way to get
mailman to spit out the full path it's actually checking for the file, but
the output of mailman-config suggests it's probably looking in the right
place.

% ./mailman-config -h
Configuration and build information for Mailman
Mailman version: 2.1.26
Build Date:      Wed May  2 13:10:19 UTC 2018
prefix:          /usr/local/mailman
var_prefix:      /usr/local/mailman
mailman_user:    mailman
mailman_group:   mailman
mail_group:      mail
cgi_group:       www-data
configure_opts: "--with-mail-gid=mail --with-cgi-gid=www-data"

I see no mention of mm_cfg.py in the mailman logs.. so nothing clearly
indicating it's failing to find the file (nor positive feedback that it has
found the file).

But I'm not convinced that's the problem anyway, since mailman clearly is
picking up the virtual host and list URL settings.   Any suggestions for
what else I should be looking at to get Mailman to pick up this config
change?

Thanks!