I get spam everyday from people who have hacked other peoples email addresses and my name is on their list of friends. Drives me nuts but it goes straight into my junk file and unopended, even tho their names on it as being contacts of mine - and it's then deleted!
That's what the spamming companies do - they get hold of an address book... and wham... spam spam spam
just don't open it, delete immediately.
Enusre you have anti virus softward on your computer and don't open anything you don't recognise. They will have got your email from any number of places... each time you sign up to something your email goes out there... and folks are clever and spam it out.
Pain in the bahookie.
Hopefully, a techie like Robert, Nick or DrewDad who are hot on these things will come along and give you a better or more understandable explaination of what to do about it.
Spam is the use of electronic messaging systems (including most broadcast media, digital delivery systems) to send unsolicited bulk messages indiscriminately. While the most widely recognized form of spam is e-mail spam, the term is applied to similar abuses in other media: instant messaging spam, Usenet newsgroup spam, Web search engine spam, spam in blogs, wiki spam, online classified ads spam, mobile phone messaging spam, Internet forum spam, junk fax transmissions, social networking spam, television advertising and file sharing network spam.
Spamming remains economically viable because advertisers have no operating costs beyond the management of their mailing lists, and it is difficult to hold senders accountable for their mass mailings. Because the barrier to entry is so low, spammers are numerous, and the volume of unsolicited mail has become very high. The costs, such as lost productivity and fraud, are borne by the public and by Internet service providers, which have been forced to add extra capacity to cope with the deluge. Spamming is universally reviled, and has been the subject of legislation in many jurisdictions.
edit: there are many threads about these scams... have a look around the board...