On 29.03.2017 08:46, Markus Armbruster wrote: > "Michael S. Tsirkin" <m...@redhat.com> writes: > >> On Tue, Mar 28, 2017 at 06:35:55PM +0100, Peter Maydell wrote: >>> Hi; it's been pointed out to me that we have a problem with qemu-devel >>> unsubscribing people because of DMARC. Specifically: >>> * microsoft.com publishes a DMARC policy that has p=reject >>> * some subscribers use mail systems that honour this and send bounces >>> for non-verifying emails from those domains >>> * the mailing list software (mailman) modifies emails that pass through >>> it, among other things adding the "[qemu-devel]" subject tag, in >>> a way that means that signatures no longer verify >>> * bounces back to mailman as a result of mailing list postings from >>> microsoft.com people can then cause people to be unintentionally >>> unsubscribed >>> >>> This is kind of painful. https://wiki.list.org/DEV/DMARC has the >>> Mailman wiki information on the subject. In an ideal world nobody >>> would use p=reject because it breaks mailing lists. In the actual >>> world we have a few choices: >>> >>> (1) I could set dmarc_moderation_action=Reject >>> * this means nobody can subscribe if they've set their dmarc policy >>> to reject (the "if you don't believe in mailing lists we don't >>> believe in you" policy). >>> * there is a certain purity to this option, in that it is pushing >>> the costs of this unhelpful mail config back on the organisations >>> which have chosen it; on the other hand I'm reluctant to make >>> life harder for people who are contributing to the project >>> and who typically don't have much say over corporate email config. >>> (2) I could reconfigure mailman to try to not rewrite anything that >>> we think is likely to be signed (in particular not the body or the >>> subject) >>> * this means dropping the [qemu-devel] tag from the subject, which I'm >>> a bit reluctant to do (it seems likely at least some readers are >>> filtering on it, and personally I quite like it) >>> * if anybody DKIM-signs the Sender: header we're stuck anyway >> >> For the record I'd strongly prefer this option - I tag all list mail >> and so "qemu-devel" appears twice: in subject and as a tag. >> Also, if mail is copied to another list, qemu-devel will >> still appear as gmail de-duplicates email by msg id. >> I can remove tags I don't care about but can't remove >> subject prefixes. > > Seconded. Mailing lists messing with the subject to "help" users with > filtering just complicate it. > > Filtering on List-Id isn't any harder, and has the added advantage that > it actually works.
The problem is that some mail clients are rather limited and you can only filter via title there - so I guess some people would complain we removed the tag from the subject. Apart from that, I've also seen mailman messing up white spaces in the body of e-mails, so this likely would only solve parts of this problem. Thomas
