My first thought upon reading this question was "Oh my god, why would you want to do that?!?" If you put your email on your SAT, you'll get more than you could ever imagine. So, for when you're a senior and are rethinking this, here's the next step: at the bottom of the email should be an "unsubscribe" link. Click it.
Also, the emails colleges send out generally are not very helpful. They all look pretty much the same and tend to blend together. You may find it more helpful to talk to your counselor about what schools are a good match for you, and then investigate them more specifically. THEN, if you're interested, get on their mailing list.
Good luck in your applications!
