How do I get rid of all of these Scam emails?

A little over six months ago, I was winning the UK lottery about three or four times a week. Now my email is bombarded with those every day along with business proposals where they want me to cash checks for them (yeah right). I am getting approx. 150 of these a week. Does anyone know how they got my address. I'm thinking it's from Monster.com or other sites I have visited. My question though: Is there any way to get rid of these and if so, how do I do it. I'm just not getting them from a few people. These are different emails coming from all over. All scams. How the heck do they get away with this. I guess it's kinda hard to catch these people. I saw a show on dateline about this and a lot of them come from Nigeria. I've been getting them from there as well as London and China. I just won a bunch of money from Queen Elizabeth's Foundation. How are people still falling for this when it's all over the place. I can understand people getting conned when it first started but come on! Help!