History of email

The history of email entails an evolving set of technologies and standards that culminated in the email systems in use today.

Computer-based messaging between users of the same system became possible following the advent of time-sharing in the early 1960s, with a notable implementation by MIT's CTSS project in 1965. Informal methods of using shared files to pass messages were soon expanded into the first mail systems. Most developers of early mainframes and minicomputers developed similar, but generally incompatible, mail applications. Over time, a complex web of gateways and routing systems linked many of them. Some systems also supported a form of instant messaging, where sender and receiver needed to be online simultaneously.

In 1971, Ray Tomlinson sent the first mail message between two computers on the ARPANET, introducing the now-familiar address syntax with the '@' symbol designating the user's system address. Over a series of RFCs, conventions were refined for sending mail messages over the File Transfer Protocol. Several other email networks developed in the 1970s and expanded subsequently.

Proprietary electronic mail systems began to emerge in the 1970s and early 1980s. IBM developed a primitive in-house solution for office automation over the period 1970–1972, and replaced it with OFS (Office System), providing mail transfer between individuals, in 1974. This system developed into IBM Profs, which was available on request to customers before being released commercially in 1981. CompuServe began offering electronic mail designed for intraoffice memos in 1978. The development team for the Xerox Star began using electronic mail in the late 1970s. Development work on DEC's ALL-IN-1 system began in 1977 and was released in 1982. Hewlett-Packard launched HPMAIL (later HP DeskManager) in 1982, which became the world's largest selling email system.

The Simple Mail Transfer Protocol (SMTP) protocol was implemented on the ARPANET in 1983. LAN email systems emerged in the mid-1980s. For a time in the late 1980s and early 1990s, it seemed likely that either a proprietary commercial system or the X.400 email system, part of the Government Open Systems Interconnection Profile (GOSIP), would predominate. However, a combination of factors made the current Internet suite of SMTP, POP3 and IMAP email protocols the standard (see Protocol Wars).

During the 1980s and 1990s, use of email became common in business, government, universities, and defense/military industries. Starting with the advent of webmail (the web-era form of email) and email clients in the mid-1990s, use of email began to extend to the rest of the public. By the 2000s, email had gained ubiquitous status. The popularity of smartphones since the 2010s has enabled instant access to emails.

Precursors The first electrical transmission of messages began in the 19th century in the form of the electrical telegraph, which started to replace earlier forms of telegraphy from the 1840s in the United Kingdom and the United States.

Telex became an operational teleprinter service in 1933, beginning in Germany and Europe, and after 1945 spread around the world.

The AUTODIN military network in the United States, first operational in 1962, provided a message service between 1,350 terminals, handling 30 million messages per month, with an average message length of approximately 3,000 characters. By 1968, AUTODIN linked more than 300 sites in several countries.

Terminology and usage The term mail in the context of messages between computer users has been in use since the 1960s. In RFCs relating to the ARPANET, network mail was used since 1973.

Historically, the term electronic mail is any electronic document transmission. For example, several writers in the early 1970s used the term to refer to fax document transmission. The Oxford English Dictionary (OED) has a first quotation for electronic mail in the modern context in 1975. Electronic mail was widely discussed in the late 1970s, but was usually shortened simply to mail. In September 1976, a Business Week article entitled When interoffice mail goes electronic remarked "In a sense, electronic mail is not new".

The OED provides a June 1979 first usage for E-mail: "Postal Service pushes ahead with E-mail" in the journal Electronics. No earlier usage has been found; although, the first usage of the term e-mail may be lost. CompuServe rebranded its electronic mail service as EMAIL in April 1981, which popularized the term. The term computer mail was also used in the early 1980s.

The June 1979 usage of E-mail referred to the United States Postal Service (USPS) project called Electronic Computer Originated Mail, which they abbreviated E-COM. USPS began looking into electronic mail in 1977 resulting in the E-COM proposal in September 1978. The service launched in 1982, allowing corporate customers to send electronic mail to a post office branch from where it was printed and delivered in the normal way. It operated until 1985.

Host-based mail systems With the introduction of MIT's Compatible Time-Sharing System (CTSS) in 1961, for the first time multiple users could log into a central system from remote terminals, and store and share files on the central disk. Informal methods of using such shared files to pass messages were soon developed and expanded into the first mail systems.

1962 The 1440/1460 Administrative Terminal System was able to exchange messages between terminals.

1965 MIT's CTSS "MAIL" command was proposed by Pat Crisman, Glenda Schroeder, and Louis Pouzin, then implemented by Tom Van Vleck and Noel Morris. Each user's messages would be added to a local file called "MAIL BOX", which would have a "private" mode so that only the owner could read or delete messages. The proposed uses of the system were for communication from CTSS to notify users that files had been backed up, discussion between authors of CTSS commands, and communication from command authors to the CTSS manual editor. Developers of other early systems subsequently developed similar mail applications. 1968 ATS/360. 1971 SNDMSG, a local inter-user mail program developed by Ray Tomlinson, incorporating the experimental file transfer program, CPYNET, allowed the first networked electronic mail over the ARPANET. The addresses contained the '@' character as a separator between local part and host. This was the first message transfer agent (MTA).* 1972 The Unix mail program enabled users to write mails and send them to mailboxes of other Unix users. Furthermore, it helped managing the mailbox of the current user. APL Mailbox, by Larry Breed of STSC, aimed at being a more robust mail software than a predecessor written in 1971. Promotional video for Scientific Time Sharing Corporation, which features President Jimmy Carter's press secretary Jody Powell explaining how the company's "APLplus Mailbox" Message Processing System enabled the 1976 Carter presidential campaign to easily move information around the country to coordinate the campaign. IBM developed a primitive in-house system for office automation over the period 1970–1972. 1973 666 BOX, by Leslie Goldsmith of I. P. Sharp Associates, a reimplementation of APL Mailbox. 1974 August - The PLATO IV Notes on-line message board system was generalized to offer "personal notes". October - IBM OFS (Office System), proving mail transfer between individuals, was first installed as a replacement for their earlier in-house office automation system. 1978 CompuServe offered electronic mail, designed primarily for intraoffice memos, as part of their corporate Infoplex service. Mail client written by Kurt Shoens for Unix and distributed with the Second Berkeley Software Distribution included support for aliases and distribution lists, forwarding, formatting messages, and accessing different mailboxes.The Mail Reference Manual, Kurt Shoens, University of California, Berkeley, 1979. It used the Unix mail client to send messages between system users. The concept was extended to communicate remotely over the Berkeley Network. Computerized Bulletin Board System (CBBS) was a public dial-up BBS. 1979 ARPANET delivermail was shipped with 4BSD. MH Message Handling System developed at The RAND Corporation provided several tools for managing electronic mail on Unix.A Mail Handling System, Bruce Borden, The RAND Corporation, 1979. September 24 - CompuServe launched a dialup service labelled MicroNET which offered electronic mail. 1980 July - Minitel experimental service launched in France, enabled users to have a mail box. Introduced commercially throughout France in 1982. Wang Laboratories introduced its Integrated Information Systems line, incorporating the ability to attach digitised voice messages. 1981 April 1 - CompuServe rebranded its electronic mail service as EMAIL. A US trademark application (USPTO SN:73432146) was filed on June 27, 1983, but abandoned in August 1984. IBM PROFS, the predecessor of OfficeVision/VM, is released, incorporating a centralised virtual machine to manage mail transfer between individuals. Before that it was a PRPQ (Programming Request for Price Quotation), an IBM administrative term for non-standard software offerings with unique features, support and pricing.By this year it had 500 users. 1982 April - HPMAIL by Hewlett-Packard went on sale. Later developed into HP DeskManager, this became the world's largest selling email system. May - ALL-IN-1 by Digital Equipment Corporation, an office automation system including functionality in electronic messaging, was released. Development work began in 1977. In-house electronic mail was in use at DEC prior to the commercial release of ALL-IN-1. 1983 April - sendmail, one of the first MTA to implement Simple Mail Transfer Protocol (SMTP), is shipped with 4.1cBSD. 1984 FidoNet is released, creating a network of connected email-accepting and -forwarding bulletin boards. Prestel Mailbox service launched, offering private messaging, on the UK Viewdata service. The Duke of Edinburgh's account would be hacked within months of launch; the resulting legal case helped to define computer misuse laws in the UK and around the world. 1994 Mar 9 - PTG MAIL-DAEMON, the first experimental Webmail services, is made available at CERN, by Phillip Hallam-Baker.

Email networks

To facilitate electronic mail exchange between remote sites and with other organizations, telecommunication links, such as dialup modems or leased lines, provided means to transport email globally, creating local and global networks. This was challenging for a number of reasons, including the widely different email address formats in use. In 1971 the first message was sent between two computers on the ARPANET. Through , , , and finally 1977's , this became a standardized working system based on the File Transfer Protocol (FTP). PLATO IV was networked to individual terminals over leased data lines prior to the implementation of personal notes in 1974. IBM VNET was deployed by 1975, using BSC to communicate among CP-67 and VM hosts running RSCS. Unix mail was networked by 1978's UUCP, which was also used for USENET newsgroup postings, with similar headers. BerkNet, the Berkeley Network, was written by Eric Schmidt in 1978 and included first in the Second Berkeley Software Distribution. It provided support for sending and receiving messages over serial communication links. The Unix mail tool was extended to send messages using Berknet. Telenet's Telemail. Tymnet's OnTyme. BITNET (1981) provided electronic mail services for educational institutions. It was based on the IBM VNET email system. 1983 – MCI Mail Operated by MCI Communications Corporation. It also allowed subscribers to send telex messages and regular postal mail (overnight) to non-subscribers."MCI Mail", MCI Mail In 1984, IBM PCs running DOS could link with FidoNet for email and shared bulletin board posting.