Comment by progval

> 3. Add those people to known blacklists so they can't register anymore domains ever again. Likewise block all domains owned already by them.

You generally can't know who operates a given domain automatically. whois is almost always redacted now.

> 4. Get domain registrars and email servers to block said domains too.

Good luck with that. They make money from spammers, and don't have any incentive to stop

I tried Namecheap twice and provided them spams with valid DKIM signatures for domains registered to them (generally on TLDs on sale for 1$, which must be sold at a loss, right?). They refused to do something about it.