Email has met tremendous popularity over the past few years. People are sending and receiving many messages per day, communicating with partners and friends, or exchanging files and information. Unfortunately, the phenomenon of email overload has grown over the past years becoming a personal headache for users and a financial issue for companies. In this chapter, we will discuss how disciplines...

The first work on email security began in 1984, which resulted the Privacy Enhanced Mail (PEM) specifications. Two years later, was done as part of Secure Data Network System (SDNS) sponsored by U.S. Government, resulting Message Security Protocol (MSP). PEM and MSP both influenced development most popular Internet protocol, is MIME (S/MIME). This article provides insight into early history sec...