Today e-mail messages flood the Internet bandwidth. According to eMarketer , 1998 saw the number of e-mail messages sent across the U.S. reach 9.4 billion each day. That’s 3.4 trillion e-mail messages in 1998 compared with the 107 billion pieces of first class mail sent in the U.S. And the most recent GVU survey now sets e-mail communications on equal footing with telephone communications.

Understanding this powerful communications infrastructure is essential for CIOs. In this primer article, we’ll give you a basic understanding of e-mail communications, providing you with the groundwork you need to know about protocols and the way e-mail travels.

The right protocol
The Internet uses a series of protocol rules that govern the transmitting and receiving of data. The Web, FTP, USENET, and e-mail are examples of Internet protocols. These let different computers and networks communicate without conflict. There are currently three major e-mail protocols used on the Internet:

  • IMAP (Internet Message Access Protocol): This strategy lets users access and manipulate e-mail or bulletin board messages from a remote mail server, providing access from home, an office workstation, or a laptop computer.
  • POP (Post Office Protocol): This protocol is used to retrieve e-mail from a mail server, allowing incoming messages only. Most e-mail software programs use the POP protocol. POP2 is a version of POP that became a standard in the 1980s and that works in conjunction with another e-mail protocol (SMTP) to send messages. POP3, a new version of POP, can operate with or without SMTP.
  • SMTP (Simple Mail Transfer Protocol): This protocol is used for sending e-mail messages over the Internet.

In addition to e-mail protocols, the TCP/IP Protocol is essential for all Internet transmissions. TCP/IP is the standard Internet protocol that helps networks communicate without problems.

The life of an e-mail message
An e-mail communication on the Internet travels at fantastic speeds. A single message can transmit from one side of the globe to the other in a matter of moments, but many factors are involved during the trip.

A single e-mail message consists of a stream of data packets. Before an e-mail message is ever sent, it is divided into these packets, each of which includes the destination address and part of the message. The packets are then transmitted individually over the Internet, often following different routes or paths to their destination. The path each packet travels is determined by factors such as backbone traffic and the quality of transmission and, therefore, it may not be the shortest route. The average e-mail message traveling across the Internet passes through ten computers before it reaches its destination. The trip can even go across networks (from an Internet backbone to a wireless network, for example), using gateways that help the networks communicate the information properly.

When all the packets reach their destination, they are recompiled into the original message. This trip of each packet across the Internet can take just a fraction of a second, but e-mail messages often take 20 minutes or more to reach an individual computer. This delay happens because most large e-mail servers work with messages in groups or queues to conserve processing time. The server lets a queue of messages build up and then, at an appointed time interval, sends them to individual users.

Additional resources
Everything E-Mail

Making Order Out of E-Mail Chaos

Accessing the Internet by Email FAQ

Stop Spam FAQ

The Coalition Against Unsolicited Commercial Email

  • Forty-eight percent of U.S. participants polled reported that they went online to access e-mail, making it the primary reason people go online. (PriceWaterhouseCoopers’ 1999 Consumer Technology survey )
  • The most recent GVU survey now sets e-mail communications on equal footing with telephone communications.
  • The most recentGVU survey shows that 99.7 percent of all Internet users have sent and received e-mail, and that 78.9 percent have received HTML e-mail.

Bruce Spencer is a freelance technical writer who has been working in the information industry since 1983 and writing about the Internet since 1995.

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