Sorry, I forgot to mention!
1) If you have a web site and you have your email on it, then you're in great danger! Spammers use special software to scan random, specially targeted by keywords web sites and find if there is any email address on the page. If they find something like "Contact us at:
mymail@mymail.com" -> you're 100% exposed to spam letters. They will send all kind of crap on your email. Remove your link from a web site or make it look as "mymail (at) mymail.com" or even better create an image with your mailbox name.
2) Spammers also send emails for selected web sites by randomly selecting inbox name, for example "support@yoursite.com" - usually such inbox names exist on all commercial web sites. Moreover, your web hosting plan usually supports redirects of all misspelled messages to one common delivery box, so an email sent to "randomname@yoursite.com" will be delivered to you anyway if re-directs turned on.
Now you know +2 ways how to protect yourself.
Regards,
Alex