Similar to other areas of IT security, messaging security continues to be a moving target for many organizations and security administrators today. Originally, spam email was seen as a major network and end-user nuisance, forcing organizations to implement some form of anti-spam solution. However, spam techniques have become far more advanced and are now able to evade many legacy anti-spam solutions. To make matters worse, spam has moved beyond a bandwidth issue and nuisance to become the key medium for malware delivery, introducing numerous threats into the corporate network. Last year, 84 percent of companies surveyed said that their networks had been affected by malware that was introduced via email1. Many organizations are also struggling to protect their customers from a variety of increasingly advanced email-based attacks such as phishing and other forms of fraud. It is clear that messaging security solutions today need to address not only new types of spam (i.e. image-based, etc.), but also a new breed of malicious email-based attacks, as well as attacks against the messaging infrastructure itself.