On 8 Apr 2014, at 05:21, John R Levine <johnl@xxxxxxxxx> wrote: > Mailing list apps can't "implement DMARC" other than by getting rid of every feature that makes lists more functional than simple forwarders. Given that we haven't done so for any of the previous FUSSPs that didn't contemplate mailing lists, because those features are useful to our users, it seems unlikely we'll do so now. Well, Mailman 2.1.16 has the FROM_IS_LIST feature that "Fixes" the problem by putting the list address in the From: field. That seems to work, except that you lose information (the sender's address) if the list wants to operate a policy of "Reply goes to list". You can then assure that DKIM signatures are valid and set up SPF, etc. This also has the effect of letting you operate through the various cloud email platforms that try to validate sender addresses. But I agree it's broken. Cheers, Sabahattin