Social Networks

E-mail accounts and addresses are provided to individuals either by organizations of which they are a part or by Internet service providers (ISPs) of one flavor or another. Some ISPs primarily provide Internet access for both e-mail and the World Wide Web, whereas others (such as AOL) provide information services of their own in addition to basic Internet access (Bunz, pp 25-95).

The basic structure of e-mail messages, which was defined in an Internet document called RFC822, includes a “header” that contains the following fields: Date, To, From, Cc (carbon copy), Subject, and Bcc (Blind carbon copy—recipients cannot see those listed in the To and Cc fields). Other kinds of files can be “attached” to the e-mail, making the message a delivery vehicle for more complexly formatted material such as spreadsheets, images, computer programs, or sound or video files. A number of methods are used for encoding such binary data so that it can be attached to or incorporated in e-mail messages. The most popular method is the Multi-purpose Internet Mail Extensions (MIME) standard. MIME extends the format of Internet mail to allow non-U.S. ASCII textual messages, nontextual messages, and multi-part message bodies to be included in message headers. BinHex and Uuencode are other methods of encoding attachments(White, pp 125-135).

Behind the individual message and its structure are the mail protocols or recipes for information exchange, as well as the network of computer servers that carry out these exchanges in conjunction with each individual's own computer software, which acts as a “client” to the server software (the client-server relationship is basic to network environments). Internet e-mail is transferred from mail server to mail server according to a protocol (standard set of rules) known as Simple Mail Transfer Protocol (SMTP), and from the server to the individual's e-mail account, software, and computer via mail retrieval protocols such as Post Office Protocol 3 (POP3) and Internet Message Access Protocol (IMAP). The individual is usually unaware of these except when setting up a personal e-mail software client such as Eudora or Outlook (Standard or Express) to mention only two of the more popular e-mail software programs. Some Web browsers also handle e-mail, and some e-mail services are Web-based (Bunz, pp 25-95). People retrieve Web-based email by using their Internet browser to go to the site of their e-mail server, log in, and receive and send mail, thus enabling access from anywhere that a Web browser ...