Yes, it is- however it could stop an automated attack where the bad agent isn’t targeting you specifically or is not a particularly knowledgeable agent. It also

Yes, it is- however it could stop an automated attack where the bad agent isn’t targeting you specifically or is not a particularly knowledgeable agent. It also might help you find out where a leak or spam is coming from (eg if you get a reset password email from John+facebooksecretlogin@gmail.com, you know your Facebook email address is known to an attacker). So it’s better than nothing.