On Tue, Dec 20, 2016 at 07:56:01PM -0000, John Levine wrote: > In article <m1cJIF7-0000DEC@xxxxxxxxxxxxxxxxxxxx> you write: > >Just a random idea, I don't think I have seen it before, but I may have missed > >it. > > > >What about adding a checkbox in the mailman profile for subscribers of the > >lists that basically says: if you detect that the sender is using DMARC then > >please rewrite the From header. > > Whether a mail system enforces DMARC policies is up to the system's > manager, not individual users. Even in the IETF, I expect that many, > perhaps a majority, of users have only the dimmest idea what if > anything their operator does with DMARC. This starts getting more complicated, but the mailing list could try intentionally sending a message which fails DMARC (e.g., with a claimed from address of example@xxxxxxxxx) to the mailing list subscriber and see if it gets bounced, and use that to set the default for that setting automatically? - Ted