Hi List Admins,
On Aug 1st mailman will be configured to improve message delivery from users whose email
provider has a strict DMARC policy (yahoo, aol, etc.). Here’s a quick breakdown of what
will change:
Messages whose original From: domain publishes a DMARC policy of p=reject or p=quarantine
will...
Have the From: header rewritten (Munged) to the posters name 'via the list'
<list_address> and
Merge the poster's address into the Reply-To: header
To reiterate, only if the senders email domain has a strict DMARC policy will the from
address be rewritten. While rewriting the from header may not be ideal this is a
necessary setting to ensure reliability of the mailing list system. Without rewriting
these messages may be lost silently, or with cryptic error DSN messages returned to the
poster. List admins may optionally choose a different moderation action on a per-list
basis.
Additional detail about mailman configuration and DMARC moderation settings be found at
https://wikitech.wikimedia.org/wiki/Mailman#DMARC_Compatibility
<https://wikitech.wikimedia.org/wiki/Mailman#DMARC_Compatibility>
Best,
—Keith
Keith Herron | Ops Engineer