[Mailman-Users] DMARC and gmail

[Richard Damon]

On 7/19/17 9:13 AM, Kevin Nowaczyk via Mailman-Users wrote:
> I've recently been hearing that some subscribers to a club mailing list who use gmail are having all messages pushed to their spam folder. One user said it's only an issue when the sender is a gmail user as well. I'm running mailman 2.1.23 and had dmarc_moderation_action set to the default value..which I think was Accept. I recently changed it to "Munge From". The dmarc_quarantine_moderation_action is set to yes, and dmarc_none_moderation_action is No. When using the old settings gmail listed messgaes as: SPF PASS, DKIM "Neutral with domain null", and DMARC FAIL, but when a non-gmail user sent a message the DMARC was not listed.
> After changing to "Munge From" it still has a DMARC fail. What are the differences that I should be seeing after changing the dmarc_moderation_action? Here is an authentication header of a message from a gmail user to a gmail user.
> ARC-Authentication-Results: i=1; mx.google.com;
>         dkim=neutral (body hash did not verify) header.i=@gmail.com header.b=dAmiQOEo;
>         spf=pass (google.com: domain of bockbrew-bounces at lists.bockbrew.com designates 65.181.121.110 as permitted sender) smtp.mailfrom=bockbrew-bounces at lists.bockbrew.com;
>         dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=gmail.com
> Thanks for any help,Kevin Nowaczyk
My experience with GMail is that a message with a broken DKIM signature 
(because of list modification of the message) will cause the message to 
be put into the spam folder unless you have your list resign the message 
or establish a SPF setting for the domain.

One warning, if you do establish SPF for your domain, then anyone who 
sets up a 'forwarding' for your list emails to gmail (or someone who 
checks SPF records) will start to bounce.

-- 
Richard Damon