Terminology and History
– ‘Electronic mail’ has been in use since 1975
– Variations of the shorter ‘E-mail’ have been in use since 1979
– ‘Email’ is now the common form and recommended by style guides
– ‘E-mail’ is falling out of favor in some style guides
– ‘Email’ was used by CompuServe starting in April 1981
– Computer-based messaging between users of the same system became possible in the early 1960s
– The first ARPANET network mail was sent in 1971, introducing the familiar address syntax
– Proprietary electronic mail systems began to emerge in the 1970s
– The Simple Mail Transfer Protocol (SMTP) was implemented on the ARPANET in 1983
– The current Internet suite of SMTP, POP3, and IMAP email protocols became the standard in 1995
Operation
– The sender formats the message and uses the submission protocol to send it to the local mail submission agent (MSA)
– The MSA determines the destination address and resolves the domain name
– The DNS server responds with MX records listing the mail exchange servers for the domain
– The message is sent to the recipient’s ISP’s MTA server
– The MDA delivers the message to the recipient’s mailbox, which can be accessed using POP3 or IMAP
Message Format
– An email consists of an envelope and content
– The content includes a header and a body
– Multipurpose Internet Mail Extensions (MIME) allow for text in other character sets and multimedia content attachments
– International email addresses using UTF-8 are standardized but not widely adopted
– Fields within emails, such as To, From, CC, BCC, were defined in RFC-680 in 1975
Email Systems
– Email operates across computer networks, primarily the Internet, and local area networks
– Today’s email systems are based on a store-and-forward model
– Users and their computers are not required to be online simultaneously
– ASCII text-only communications evolved to support multimedia content
– Webmail services provide an alternative way to access email
Miscellaneous
– ‘Email’ is the recommended spelling, replacing ‘E-mail’
– CompuServe started using ‘Email’ in April 1981
– The current email protocols (SMTP, POP3, and IMAP) became the standard in 1995
– Email can be accessed using POP3 or IMAP
– Webmail services provide an alternative way to access email
Electronic mail (email or e-mail) is a method of transmitting and receiving messages using electronic devices. It was conceived in the late–20th century as the digital version of, or counterpart to, mail (hence e- + mail). Email is a ubiquitous and very widely used communication medium; in current use, an email address is often treated as a basic and necessary part of many processes in business, commerce, government, education, entertainment, and other spheres of daily life in most countries.
Email operates across computer networks, primarily the Internet, and also local area networks. Today's email systems are based on a store-and-forward model. Email servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need to connect, typically to a mail server or a webmail interface to send or receive messages or download it.
Originally an ASCII text-only communications medium, Internet email was extended by Multipurpose Internet Mail Extensions (MIME) to carry text in other character sets and multimedia content attachments. International email, with internationalized email addresses using UTF-8, is standardized but not widely adopted.
