Spam definitely is a fundamental problem of all open-inbox systems like email.
Spam definitely is a fundamental problem of all open-inbox systems like email.
To my knowledge, these systems are proprietary, obscure secret sauce heuristics. My point is that we should find a way to do spam prevention in an open and easy to implement way. Such an algorithm could then be applied to any open-inbox system, not just email.
How is a malicious actor going to set up a fake SPF record for my domain without compromising my DNS account?
It makes sense to block a domain even with a correct SPF record. It makes no sense to block an IP with a correct SPF record for a domain that you already trust. And, like I said, I'm getting bounced mail from people I've been corresponding with for years, so I know the recipient email providers do trust the domain. They're just being stupid with IP black listing.