Well, it depends on where you left your email. A lot of companies sell your email for advertising purpose. They make a little money per email and you get bombarded with Spam/Junk etc.
I have two Hotmail email addresses that I use primarily for those purposes and do not use them for important things. My Spam detector filters everything I do not want out and sends it right away in the junk folder. I do not even look in that one anymore.
With a well trained spam filter and the junk folder emptied every other day, I am pretty save from all that crap.