Why Follow the Internet Mail Model?
Unlike closed commercial mail systems, Internet messaging is defined by a series of specifications that are free and open for all. Consequently, an Internet messaging system can be built using a variety of products from several vendors, with assuring that each product will interoperate with all the other products. This is especially important because the open standards defining the Internet itself make for a highly complex environment in which each component of a messaging model must know what to expect of the others. Communication standardization is the soul of the Internet.
The Internet repeatedly proves the fact that there is no problem so large that it cannot be solved by the principle of “divide and conquer.” A browse through some of the messaging-related RFCs from the early 1970s shows how early ARPAnet[1] engineers struggled to send email back and forth. Early on, they relied on the weak model embraced by many modern-day closed-source solutions: email as a file-copying program. RFC 469 (circa 1973) kicks around the idea of an email infrastructure based on passing files around using FTP. Even in those early discussions, innovative ideas were alluded to, such as active links to other documents, redirection to central document repositories,[2] permanent email archives, and content from arbitrary non-textual sources. Those ideas suggested the need for a hierarchy of standards and protocols.
Before too long, however, the problem of how to best ...