mail: see postal service.

electronic mail or e-mail, the electronic transmission of messages, letters, and documents. In its broadest sense electronic mail includes point-to-point services such as telegraph and facsimile (fax) systems. It is commonly thought of, however, in terms of computer-based message systems where the electronic text file that is received can be edited, replied to, excerpted, or even pasted into another electronic document that can be used or manipulated by a word processor, desktop publishing system, or other computer program. Users of such systems, called store-and-forward or mailbox systems, can broadcast messages to multiple recipients, read and discard messages, file and retrieve messages, or forward messages to other users. Extensions to e-mail allow the user to add graphics and sound to messages, and files can be attached to e-mails. Computer-based messaging can take place on a single computer, a computer network, or across gateways linking different computer networks (as through the Internet). With the increasing use of e-mail, unsolicited commercial e-mail, known as spam, has become a significant problem. E-mail, especially through attachments, has also become a means for disseminating computer viruses and other malicious programs.

e-mail: see electronic mail.

or mail

Form of body armour worn by European knights and other medieval warriors. An early form, made by sewing iron rings to fabric or leather, was worn in late Roman times and may have originated in Asia. Medieval armourers interlaced the rings, which were closed by welding or riveting. In the 8th century, mail was a short coat with a separate sleeve for the sword arm. By the Norman Conquest (1066), the coat was long and fully sleeved; a hood, usually fitting under a helmet, covered the head and neck. By the 12th century, mail was fitted to hands, feet, and legs. The addition of plates to increase chest and back protection gradually evolved in the 14th century into complete plate armour, displacing mail.

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in full electronic mail

Messages and other data exchanged between individuals using computers in a network. An e-mail system allows computer users to send text, graphics, and sometimes sounds and animated images to other users. It developed from large organizations using an internal messaging system as a communication link among employees. The mass provision of e-mail addresses for private individuals by Internet service providers led to the development of e-mail as a system to supplement or replace communication by letter.

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