Email Viruses are contained in attachments sent to an email account, generally by a self contained executable file. Once opened (or executed) the effects can be mild (such as the Microsoft Word Macro Virus) which affects Word documents only to the extreme of attacks on the operating system and then propagates through the network and/or goes through your address book and sends itself to the addresses. (please see side bar for the list of the current top 10 viruses)

With email viruses, there are times when you are not even aware that a virus is on your machine, Symtrex has witnesses one user having over 300 files infected, and some program files, before they even realized that the machine was infected. Some viruses now have the ability to turn-off your antivirus software running locally on your machine. What ends up happening is a user is given a false sense of security with the antivirus software which they think is running. Unless a user takes the time to manually apply all updates on packaged software, it can become obsolete rather quickly.