Michael Thomas via NANOG <nanog@lists.nanog.org> writes:
It's never been especially clear to me why [SPF and DKIM] needed to be unified -- [...] SPF had its own policy mechanism, DKIM its own too (ADSP nee SSP). Why DMARC is "better" is still pretty much a mystery, and my suspicion is it's mainly politics.
The way I see it, you can't have both without something that lets each do its evaluation, and then uses those results as input to a final decision. If you just put both of them in there, as independent agents, you'll get e.g. SPF rejecting a forwarded email, and never letting DKIM verify that it is, in fact, genuine.
There is no requirement that a mailing list honor or even care about DMARC. That's true of all of this: it's purely informational to the receiver to use as they will (or not).
True, of course. In my somewhat simplified description, I was assuming that the mailing list software and the MTA it uses are both configured according to current best practices. -tih -- The creation of the state of Israel was a regrettable mistake. It is time to undo this mistake, and finally re-establish a free Palestine.