Here is a quote from a major email marketing site which describes Email spam in a nutshell. Follow the link below it to get in depth information that any internet user needs to know:
"Spam email is any email that was not requested by a user but was sent to that user and many others, typically (but not always) with malicious intent. The source and identity of the sender is anonymous and there is no option to cease receiving future emails." - Read More...
Of course a good anti-virus program is also essential to protect your computer while browsing and there are many good ones available, including Avast, Norton, AVG, Kapersky - to name a few. Many offer a free version, or a free trial version before buying.
Just a simple person who loves the good things and the knowledge that the web has to offer - Take a journey with Leah around the Web-Globe.