FYI, I'm intending to make this change tomorrow (Thursday Jan 16th) On Fri, Jan 10, 2020 at 12:26:07PM +0000, Daniel P. Berrangé wrote: > Hi List Subscribers, > > In recent months we have been seeing an increasing number of bounced > deliveries from libvirt mailing lists[1] due to DMARC policies on list > subscriber's mail servers. IOW, many subscribers are only receiving > a subset of mails sent to the libvirt mailing lists. > > We believe the root cause of many of the problems is that mailman is > modifying the mail subject to add the "" / "[libvirt-users]" > prefix, and modifying the mail body to add the footer with links to > the listinfo page. > > These modifications invalidate the DKIM signatures on mails sent to > the list by some of our subscribers. This in turn causes DMARC policy > rejections by the destination SMTP servers when mailman delivers > messages. > > The solution is to disable any feature in mailman which modifies > parts of the mail validated by the DKIM signature. This means removing > the subject prefix and the mail body header. Further information on > this approach can be seen here: > > https://begriffs.com/posts/2018-09-18-dmarc-mailing-list.html > > QEMU has made the same change on their mailing list last year: > > https://lists.gnu.org/archive/html/qemu-devel/2019-09/msg00416.html > > If you are currently doing mail filtering / sorting based on the subject > prefix, you will need to change to use the List-Id header instead. > > I will wait until the latter part of next week before making this change > to allow people time to adapt any filters. > > Regards, > Daniel > > [1] technically moderators have only been seeing bounces for messages on > libvirt-users-list, but that's because we've got mailman configured > to send libvir-list bounces to /dev/null. > -- > |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| > > -- > libvir-list mailing list > libvir-list@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/libvir-list Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
