[omaha] Fwd: GNU Mailman email lists at mail.python.org

[Jeff Hinrichs - DM&T]

The mail list software has been updated.  This is dealing explicitly with
handing ISP who use DMARC settings (yahoo, aol).
I've enabled munging for those users who are emailing from one of these
"helpful" ISPs.

Please review the information and forward any comments to the list.

Best,
Jeff


---------- Forwarded message ----------
From: Mark Sapiro <mark at python.org>
Date: Tue, Apr 28, 2015 at 5:21 PM
Subject: GNU Mailman email lists at mail.python.org
To: jeffh at dundeemt.com


Hello jeffh at dundeemt.com,

This is Mark Sapiro, GNU Mailman developer and primary supporter
of the Mailman 2.1 branch.

I am writing to you because you are an owner of a list hosted at
mail.python.org.

This list is:

omaha at python.org

I want to inform you of an upcoming change to Mailman on
mail.python.org.

You may be aware of DMARC and it's affects on mailng lists. If not,
<http://wiki.list.org/DEV/DMARC> is a place to start to learn more.

In April, 2014, Yahoo.com and later AOL.com changed their DMARC policies
to 'reject' which caused much email From: addresses in those domains that
passed through mailing lists to be rejected by recipient's ISPs causing
much pain for list members and list owners.

The postmasters at python.org responded to this by appending .dmarc.invalid
to the From: domains yahoo.com, aol.com and a couple of others to avoid
having this mail ultimately rejected by recipient ISPs.

Mailman also responded to this by implementing a new feature,
dmarc_moderation_action, to allow munging of the From: address of posts
From:
domains that publish DMARC p=reject and optionally p=quarantine policies
and other possible actions for such messages. This was an extension of a
previously implemented from_is_list feature which was never widely used and
is now deprecated.

Our plan going forward is to set dmarc_moderation_action to Munge From on
all
lists and set the site default the same. This will mean list owners will be
able to set stronger actions for this but will not be able to simply Accept
such mail without some modification being done to the sending domain.

One list has already set dmarc_moderation_action to Munge From, but it has
not yet been effective because of the .dmarc.invalid munging that's been
done.

Please visit the Privacy options... -> Sender filters -> (Details for
dmarc_moderation_action) link in your list's admin UI and/or the above wiki
page for more info on these settings.

At the same time, we will discontinue appending .dmark.invalid to those
From:
domains.

These changes are designed to have the minimum possible impact on your
lists.
Mail from domains that don't publish DMARC p=reject or quarantine policies
will be unaffected and for that which is affected, the changes are designed
to interact with existing settings such as Reply-To: munging in a way that
should not change the behavior of client's 'reply' and 'reply all'
functions.

Please do not hesitate to contact me if you have questions about this
change.

--
Mark Sapiro
mark at python.org



-- 
Best,

Jeff Hinrichs
402.218.1473