> On Sep 30, 2015, at 5:39 PM, John Levine <jo...@taugh.com> wrote: > >>> The local signer here must know this message goes to dmarc@ietf.org >>> an add a signature including "!fs=ietg.org" >> >> An average email author cannot be relied on to cause this setting to be >> made. > > Quite correct. I would expect conditional signatures to be applied by > large mail systems, using their private list of domains that look like > mailing lists to decide who gets them.
How much of a barrier to entry to new or small mailing list providers (or new domains being used there) does this cause? > From the past couple of years of discussion, it is clear that all of > the large mail systems already have such a list of domains, so the > implementation should be straightforward. > > Small domains may not, in which case there's a variety of ways they > could approximate it, e.g., sniff incoming mail for stuff that looks > like list mail to create a list, cooperate on a shared database of > mailing list domains, or most likely admit that they are too small to > be phish targets so publishing a DMARC policy is counterproductive. Cheers, Steve _______________________________________________ dmarc mailing list dmarc@ietf.org https://www.ietf.org/mailman/listinfo/dmarc
