The most important threat vector

Email is the most important business communication method. The mainstream adoption of fax machines and then email changed the business world and greatly accelerated economic activity. Email is largely responsible for shrinking the globe. Before email and fax machines, if a US company wanted to communicate with a company in India, the team would either need to make very expensive trips or phone calls or send messages through traditional mail and wait 30 days for a response. The fax machine enabled near-instant communication, but it was an imperfect technology. Email allowed messages to be sent around the globe in 30 seconds, which greatly accelerated the global business cycle. It could be said that globalization as we know it today would not be possible without email.

Since email is so widely used and critical to business operations, it is also the most attacked part of a corporate infrastructure. Because email is a business-critical application...