[Mailman-Users] 2.1.18 internal documentation suggestions

Mark Sapiro mark at msapiro.net
Fri May 2 05:29:30 CEST 2014

Here's what I've got. I didn't change the name of the setting, but I
changed its description and all the detail. I now have

from_is_list (general): 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.

Several protocols now in wide use attempt to ensure that use of the
domain in the author's address (ie, in the From: header field) is
authorized by that domain. These protocols may be incompatible with
common list features such as footers, causing participating email
services to bounce list traffic merely because of the address in the
From: field. *This has resulted in members being unsubscribed despite
being perfectly able to receive mail.*

The following actions are applied to all list messages when selected
here. To apply these actions only to messages where the domain in the
From: header is determined to use such a protocol, see the
dmarc_moderation_action settings under Privacy options... -> Sender filters.


    Do nothing special. This is appropriate for anonymous lists. It is
appropriate for dedicated announcement lists, unless the From: address
of authorized posters might be in a domain with a DMARC or similar
policy. It is also appropriate if you choose to use
dmarc_moderation_action other than Accept for this list.
Munge From
    This action replaces the poster's address in the From: header with
the list's posting address and adds the poster's address to the
Reply-To: header.
Wrap Message
    Just wrap the message in an outer message with the From: header
containing the list's posting address and with the original From:
address added to the Reply-To: header and with Content-Type:
message/rfc822. This is effectively a one message MIME format digest.

The transformations for anonymous_list are applied before any of these
actions, so if actions other than No are applied on an anonymous list,
they will apply to the anonymized message.

The Reply-To: header munging actions below interact with these actions
as follows:

first_strip_reply_to = Yes will remove all the incoming Reply-To:
addresses but will still add the poster's address to Reply-To: for all
three settings of reply_goes_to_list which respectively will result in
just the poster's address, the poster's address and the list posting
address or the poster's address and the explicit reply_to_address in the
outgoing Reply-To: header.

[Note: is the above what we want? I think so, but others are adding a
header something like X-Mailman-Originally-From: (see the "The future
options for mailing list managers" section at

These actions do not apply to messages in digests or archives or sent to
usenet via the Mail<->News gateways.

If dmarc_moderation_action applies to this message with an action other
than Accept, that action rather than this is applied

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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