) The transmission of text messages from sender to recipient. Email messages can also be formatted with graphics like a brochure or Web page, an enhancement that many users like, but that creates more spam and a security risk (see HTML email
Users can send a mail message to a single recipient or to multiple users. In addition, JPEG photos as well as any other type of computer file may be attached to the message (see email attachment
). Mail is sent to a simulated mailbox in the organization's mail server until it is downloaded to the "in" mailbox in the user's computer.
The Messaging System and the Client
An email system requires a messaging system, which is primarily a store and forward capability based on the Internet's Simple Mail Transfer Protocol (SMTP). A mail program (email client), such as Windows Mail, Mac Mail, Outlook and Eudora, provides the user interface for mailboxes and send and receive functions. Popular email services such as Gmail and Yahoo! Mail are Web based, in which case the Web browser is used as the mail program (see email interfaces
The Internet Changed It All
The Internet revolutionized email by turning countless incompatible islands into one global system. Initially serving its own users, in the mid-1990s, the Internet began to act as a mail gateway between the major online services such as CompuServe and America Online (AOL). It then became "the" messaging system for the planet. In the U.S., Internet mail is measured in the trillions of messages each year. See email vs. fax
, messaging system
, instant messaging
, read receipt
and self-destructing email
The First Email on the Internet
In 1971, the first email message was typed into the Teletype terminal connected to the Digital Equipment PDP-10 toward the back of the room in the following picture. The message was transmitted via ARPAnet, the progenitor of the Internet, to the PDP-10 in front. Dan Murphy, a Digital engineer, took this photo in the Bolt, Beranek and Newman datacenter. See ARPAnet
Could They Have Imagined Spam?
When they sent this first message in 1971, could they have imagined the trillions of email messages that would follow in years to come? (Image courtesy of Dan Murphy, www.opost.com/dlm)