Jon Baron writes:
I think what I have just said speaks to your question. If not, then I don't understand your question.
It wasn't a question. It was a statement that a technical solution exists that might be useful to some site administrators in relatively unusual circumstances.
Now for a rant on the subject of spam blocking.
[ agreed! ]
In sum, totally blocking "spam" from the recipient, on the basis of some fallible algorithm that guesses what is spam, is outrageous.
And semi-popular with users while being cheap for providers, which was my other point. So, good luck doing anything about it. :-(
Let's put it this way: one of the few things my (ultimate) employer has done right in terms of Internet security was banning in April 2014 the use of Yahoo! addresses for communication within all educational institutions in Japan. And I haven't seen any (internally) since. :-) But it takes that level of power to do anything about sucky providers.
And ... uh, well ... they actually got it *wrong*: Yahoo! Japan franchised the name and some of the software, but otherwise is independent of international Yahoo!, and to this day
% host -t TXT _dmarc.yahoo.co.jp _dmarc.yahoo.co.jp descriptive text "v=DMARC1; p=none; \ <= !!!!! rua=mailto:firstname.lastname@example.org"
This is the cockeyed Internet we have. It's wishful thinking to think otherwise. Im theory, it *could* be *much* better, but it's not going to "just happen". We have to build it ourselves. That's why we (Mailman) are here. Not that we're terribly important, or even all that good at it, but https://gitlab.com/mailman is open for merge requests if you can do a better job. :-)
By the way, that's a happy smiley, not a snarky smiley trying to imply "quitcherbitchin and code" or anything like that.