Alternative spellings

• email

Noun

Singular e-mail

Plural countable and uncountable; plural e-mails

e-mail (countable and uncountable; plural e-mails)

1. (uncountable) A system for transferring messages from one computer to another, usually via a network.

   He sent me his details via e-mail.

   The advent of e-mail has simultaneously brought our society closer together and farther apart.

2. (countable, see Usage notes below) A message sent via an e-mail system.

   I am searching through my old e-mails.

   He sent me several e-mails last week to that effect.

3. (uncountable, see Usage notes below) A quantity of e-mail messages.

   I am searching through my old e-mail.

   My inbox used to only allow 50 MB of e-mail at a time until last year, when they upgraded it to 2 GBs!

4. (informal) An e-mail address.

   What's your e-mail?

Electronic mail, commonly called email or e-mail, is a method of exchanging digital messages across the Internet or other computer networks. Email systems are based on a store-and-forward model in which email server computer systems accept, forward, deliver and store messages on behalf of users, who only need to connect to the email infrastructure, typically an e-mail server, with a network-enabled device for the duration of message submission or retrieval. Originally, email was transmitted directly from one user's device to another user's computer, which required both computers to be online at the same time.

An electronic mail message consists of two components, the message header, and the message body, which is the email's content. The message header contains control information, including, minimally, an originator's email address and one or more recipient addresses. Usually additional information is added, such as a subject header field.

Originally a text-only communications medium, email was extended to carry multi-media content attachments, which was standardized in RFC 2045 through RFC 2049, collectively called, Multipurpose Internet Mail Extensions (MIME).

The foundation for today's global Internet email services reaches back to the early ARPANET and standards for encoding of messages were proposed as early as 1973 (RFC 561). An e-mail sent in the early 1970s looked very similar to one sent on the Internet today. Conversion from the ARPANET to the Internet in the early 1980s produced the core of the current services.

Network-based email was initially exchanged on the ARPANET in extensions to the File Transfer Protocol (FTP), but is today carried by the Simple Mail Transfer Protocol (SMTP), first published as Internet standard 10 (RFC 821) in 1982. In the process of transporting email messages between systems, SMTP communicates delivery parameters using a message envelope separately from the message (header and body) itself.