Commonly called SPAM.
NEVER follow any link from those messages.
If you do, you validate your address and will receive even more SPAM.
ALWAYS signal those as spam. If you use some web-mail, there is a "Signal as SPAM" button, normaly at the top.
If you use the microsoft mail application, switch to another one like Thunderbird that have an adaptive SPAM filter that can automaticaly delete those messages.
Electro, April 2011