Junk Mail

I really get tired of junk mail in my inbox!! I know some people who actually switch e-mails because they get so much junk mail. Sometimes I'm tempted...and would if I didn't have so many contacts who already knew my e-mail address. I'm not even sure where all of these e-mails come from?! It seems like the junk mail filter that is supposed to work, doesn't do a thing. I still get SO much! If anyone has any suggestions that's worked for them...please let me know!