I don't really bother with trying to prevent spammers from getting my email as I just see it as a losing battle. Like besides having the actual email address posted somewhere online they can also get it if you have it mentioned in your cookies (would be pretty dumb for a site to do that but anyway), gain access to the email lists of a site you're registered to (or assume that the site doesn't share or sell their emails), hacking someone that knows your email, etc.

I also doubt that the [at][dot] would be good enough. You'll sometimes see people going as far as you represent their emails as code (i.e. you'll need to run it to get it).

Personally I think you're better off trying to filter the spam rather than worrying about the other stuff.