Why is everyone outraged when Google/Microsoft/Yahoo and others have scraped the whole internet for two decades and are also massively profiting from that data?

If possible it might be better to set the mail server to deliver to a special inbox but report the delivery as failed to the sender.

That way you get visibility on what might have gotten in there, while also getting marked as dead for anyone trying to send to it.

If nothing came in after a year or two, it’s probably safe to throw away.