Hi Slavo, p=none is not always harmless. Some message filters treat p=none differently to not having DMARC. For example, Alice periodically treats p=none as equivalent to p=reject. Or there is an ISP who junks mail from domains with an RUA pointing to a freemail account, regardless of the policy. They are perhaps, rare, and extreme cases but there are more than a few providers that don't implement DMARC correctly and don't send reports either - messages just don't reach the inbox.
So, in this case, where I know absolutely zero about the poster's MLM audience etc., I recommend no DMARC record at all. It gives the best possible chance of the mailing list messages achieving inbox placement. Plus, most list operators don't have the time to be lecturing/mediating/pleading with ISPs who are blocking messages because don't understand DMARC. Of course, maybe the lists in question have a risk profile that would justify DMARC. If so, then it should be deployed fully, not just left lingering at p=none. I do have a client where we implemented DMARC with p=reject on their lists. But they are not public lists, and the recipients belong to a very limited number of known domains. Ken. > -----Original Message----- > From: mailop <mailop-boun...@mailop.org> On Behalf Of Slavko via mailop > Sent: Tuesday 14 June 2022 18:08 > To: mailop@mailop.org > Subject: Re: [mailop] Best practice for mailing list servers > > Ahoj, > > Dňa Tue, 14 Jun 2022 16:51:55 +0000 Ken O'Driscoll via mailop > <mailop@mailop.org> napísal: > > > I wouldn't suggest that you implement DMARC on your list domain as it > > won't help with deliverability and will just cause more issues. It's > > not really designed for mailing lists. > > Please, what issues will cause DMARC with policy None? Would not be > better to suggest this instead of no DMARC? > > regards > > -- > Slavko > https://www.slavino.sk _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
