[Mailman-Developers] MM3 DMARC mitigations

Mark Sapiro mark at msapiro.net
Tue Nov 8 00:00:49 EST 2016

On 11/07/2016 06:05 PM, Barry Warsaw wrote:
> With some verbiage massaging perhaps, I am supportive of a "hammer" option
> such as this.  Maybe we can't enable it by default, but I don't think it's
> unreasonable for site/list admins to be able to be more proactive in their
> rejection of such messages.  It will probably make no difference, but if we
> can inform users as to the real culprits in this mess, they can either
> complain to their ISPs or vote with their feet and find a new provider.  That
> won't happen if they continue to blame the list software or site.

It's in MM 2.1 and it's in my dmarc branch MR
<https://gitlab.com/mailman/mailman/merge_requests/215>. The list has
dmarc_moderation_action with possible values none, munge_from,
wrap_message, reject or discard.

The default reason is not what Steve proposes. The default is in
mailman/rules/dmarc.py per

        reason = (mlist.dmarc_moderation_notice or
                  _('You are not allowed to post to this mailing '
                    'list From: a domain which publishes a DMARC '
                    'policy of reject or quarantine, and your message'
                    ' has been automatically rejected.  If you think '
                    'that your messages are being rejected in error, '
                    'contact the mailing list owner at ${listowner}.'))
        msgdata['moderation_reasons'] = [wrap(reason)]

As it is, the list can supply its own reason. The default could of
course be changed or made a configuration setting.

Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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