"If I got a bounced back message I would think "shit, he blocked me. I'd better send from a different email address". I'm not sure which gets the most pay-off,

"If I got a bounced back message I would think "shit, he blocked me. I'd better send from a different email address". I'm not sure which gets the most pay-off, I guess it depends on the stalker, but redirection effort means they have to do some effort." You're talking about someone who's extremely mentally ill and ungrounded in reality. I'd be worried about them putting more effort in.