Email, or electronic mail, is a message sent from one computer to another over a computer network . Email (also spelled e-mail) messages can be sent and received over a private network, such as one operated within a company, or over a public network, such as the internet. A message can consist of text only, or it may include one or more attached files containing text, illustrations, sound clips, or video.
To send and receive email messages, an individual must have an email address. Such an address serves the same function that a street address does for traditional mail delivery. Companies called internet service providers (ISP’s) generally offer their customers email addresses along with internet connections. A number of other companies offer free web-based email addresses supported by advertising.
Files called electronic mailboxes store delivered email on a networked computer. To read a message, a user opens the file attached to his or her address. The user can generally respond to the message by hitting a “reply” button. Users can send emails to one individual at a time or to many, depending upon how many email addresses they type into message headings.
As email became more widely used, many companies began to send unsolicited email messages to long lists of users. These messages are often called spam. Most spam consists of advertisements that direct users to an internet site where they may purchase a product or service. Processing a large volume of messages sent by “spammers” slows the servers (computers that distribute information) at ISP’s and other companies. An increase in spam can thus result in slower service for subscribers as well as in a need to delete the unwanted “junk mail.” Several countries have enacted laws designed to reduce spam by placing strict controls on the use of email to send unsolicited advertisements. Filters on email systems can automatically detect and delete some spam.
