(If the originating domain is expressly *not* OK with the
redistribution, the mailing list should bounce the message back to the
author saying as much.)
Isn't that exactly what p=reject implies? If so, the logical behaviour
for all list software would be to check the DMARC record for the
originating domain of each message, and bounce it if p=reject.
That's certainly been mentioned a lot of times and is certainly consistent
with what p=reject says it means.
The problem is pragmatic: there are a lot of people who use Yahoo's
mail, very few of them understand the technology very well, and they'd
see this as just another baffling thing that happens on their
computers. I would like to encourage all of the Yahoo users on my
lists to find a better provider, but that will take years. In the
meantime, the church has a lot of meetings to organize. It's a market
power problem, not a technical problem.
R's,
John