It's impossible for them to stop if you list your email on there. They could make it harder of course. But if you put your email out there for a human to find, then a script or bot or also find it.
And yes of course they can also stop a specific spammer. But that spammer may pick up another account and email.
And yes of course they can also stop a specific spammer. But that spammer may pick up another account and email.