Proposal: Fix mailing list & DMARC interactions
Over the last few years we've responded to multiple issues requesting help to resolve issues related to mailing lists and newer SPAM fighting techniques like DMARC which prevent messages from getting delivered, or incorrectly tag them as SPAM.
In these specific cases we've enabled a feature that instructs the mailing list to replace the 'From:' header in any message sent by a list user whose domain publishes a DMARC policy set to 'Reject/Quarantine'. While that does help it can break the expected 'reply-to' functionality(ie: that replies will be sent to the poster and not to the list).
Unfortunately this issue is likely to continue or worsen so we'll need to pick a solution from the following options:
- Enable the above feature for all mailing lists.
- Configure the mailing lists to replace the From: & Reply-To: headers to be the list address for all messages sent to the list.
While option 1 helps, it puts some burden on the list users to check where their replies are actually going. Depending on the list population this may have the same effect as option 2(if all list members domains have a DMARC 'Reject/Quarantine' policy), which means different lists might appear to function differently.
Option 2 really disrupts all our expectations of how lists should work(and have worked traditionally), but it does so equally across all lists, and may be a more durable long term solution to this issue.
Let us know which option you'd prefer.