Spamming isn't illegal. In fact, it can teach you a lot about marketing. I'm actually impressed than an 18 year old could make enough with it to pay for school.
http://en.wikipedia.org/wiki/E-mail_spam_legislation_by_coun...
Of course, you realize that could, at an extreme, mean that you cannot send a personal email to someone else you have previously not corresponded with.
Spamming refers to sending unsolicited email. Sending unsolicited emails isn't illegal; sending unsolicited emails that do not adhere to the law is illegal in America.