History of email

The history of email extends over more than 50 years, entailing an evolving set of technologies and standards that culminated in the email systems we use today.

Computer-based mail and messaging became possible with the advent of time-sharing computers in the early 1960s, and 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. Many US universities were part of the ARPANET, which aimed at software portability between its systems. That portability helped make the Simple Mail Transfer Protocol (SMTP) increasingly influential.

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, once the final restrictions on carrying commercial traffic over the Internet ended in 1995,^[1][2] a combination of factors made the current Internet suite of SMTP, POP3 and IMAP email protocols the standard.

Precursors

Early dedicated machines and networks for sending text messages existed in the form of the telegraph, Telex and AUTODIN.

Telex became an operational teleprinter service in 1933, and after 1945 spread around the world.^[3]

The AUTODIN network, 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. ^[4] By 1968, AUTODIN linked more than 300 sites in several countries.

Host-based mail systems

With the introduction of MIT's Compatible Time-Sharing System (CTSS) in 1961,^[5] for the first time multiple users could log into a central system^[6] from remote terminals, and store and share files on the central disk.^[7] Informal methods of using this to pass messages were soon developed and expanded:

• 1965 – MIT's CTSS "MAIL" command by Pat Crisman, Glenda Schroeder, and Louis Pouzin.^[8] 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 proto-email 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 developed similar email applications:

• 1962 – 1440/1460 Administrative Terminal System^[9]
• 1968 – ATS/360^[10][11]
• 1971 – SNDMSG, a local inter-user mail program incorporating the experimental file transfer program, CPYNET, allowed the first networked electronic mail^[12]
• 1972 – Unix mail program^[13][14]
• 1972 – APL Mailbox by Larry Breed of STSC.^[15][16][17]
• 1973 – 666BOX by Leslie Goldsmith of I. P. Sharp Associates, a reimplementation of APL Mailbox.^[18]
• 1974 – The PLATO IV Notes on-line message board system was generalized to offer 'personal notes' in August 1974.^[4][19]
• 1978 – 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.^[20] It used the Unix mail client to send messages between system users. The concept was extended to communicate remotely over the Berkeley Network.^[21]
• 1979 – EMAIL, an application written by Shiva Ayyadurai for the University of Medicine and Dentistry of New Jersey. He claims to have "invented" email due to certain functionality in the program, but these claims are disputed.^{[22][23][24][25][26]}
• 1979 – MH Message Handling System developed at RAND provided several tools for managing electronic mail on Unix.^[27]
• 1981 – PROFS by IBM^[28][29]
• 1982 – ALL-IN-1^[30] by Digital Equipment Corporation
• 1982 – HP Mail (later HP DeskManager) by Hewlett-Packard^[31]

LAN email systems

In the early 1980s, networked personal computers on LANs became increasingly important. Server-based systems similar to the earlier mainframe systems were developed. Examples include:

• cc:Mail
• LANtastic
• WordPerfect Office
• Microsoft Mail
• Banyan VINES
• Lotus Notes

Eventually these systems could link different organizations as long as each organization ran the same email system and proprietary protocol.^[32]

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 ARPANET email was sent,^[33] and through RFC 561, RFC 680, RFC 724, and finally 1977's RFC 733, became a standardized working system.
• PLATO IV was networked to individual terminals over leased data lines prior to the implementation of personal notes in 1974.^[19]
• Unix mail was networked by 1978's uucp,^[34] 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.^[21]
• The delivermail tool, written by Eric Allman in 1979 and 1980 (and shipped in 4BSD), provided support for routing mail over dissimilar networks, including Arpanet, UUCP, and BerkNet. (It also provided support for mail user aliases.)^[35]
• The mail client included in 4BSD (1980) was extended to provide interoperability between a variety of mail systems.^[36]
• BITNET (1981) provided electronic mail services for educational institutions. It was based on the IBM VNET email system.^[37]
• 1983 – MCI Mail Operated by MCI Communications Corporation. This was the first commercial public email service to use the internet. MCI Mail also allowed subscribers to send regular postal mail (overnight) to non-subscribers.^[38]
• In 1984, IBM PCs running DOS could link with FidoNet for email and shared bulletin board posting.

Attempts at interoperability

Early interoperability among independent systems included:

• ARPANET, a forerunner of the Internet, defined protocols for dissimilar computers to exchange email.
• uucp implementations for Unix systems, and later for other operating systems, that only had dial-up communications available.
• CSNET, which initially used a purpose-built dial-up protocol, called Phonenet, to provide mail-relay services for non-ARPANET hosts.
• Action Technologies developed the Message Handling System (MHS) protocol. This was later bought by Novell,^[39][40][41] but they abandoned it after purchasing the non-MHS WordPerfect Office—which they renamed Groupwise.
• HP OpenMail was known for its ability to interconnect several other APIs and protocols, including MAPI, cc:Mail, SMTP/MIME, and X.400.
• Soft-Switch released its eponymous email gateway product in 1984, acquired by Lotus Software ten years later.^[42]
• The Coloured Book protocols ran on UK academic networks until 1992.
• X.400 in the 1980s and early 1990s was promoted by major vendors, and mandated for government use under GOSIP, but abandoned by all but a few in favor of Internet SMTP by the mid-1990s.

From SNDMSG to MSG

In the early 1970s, Ray Tomlinson updated an existing utility called SNDMSG so that it could copy messages (as files) over the network. Lawrence Roberts, the project manager for the ARPANET development, took the idea of READMAIL, which dumped all "recent" messages onto the user's terminal, and wrote a programme for TENEX in TECO macros called RD, which permitted access to individual messages.^[43] Barry Wessler then updated RD and called it NRD.^[44]

Marty Yonke rewrote NRD to include reading, access to SNDMSG for sending, and a help system, and called the utility WRD, which was later known as BANANARD. John Vittal then updated this version to include three important commands: Move (combined save/delete command), Answer (determined to whom a reply should be sent) and Forward (sent an email to a person who was not already a recipient). The system was called MSG. With inclusion of these features, MSG is considered to be the first integrated modern email programme, from which many other applications have descended.^[43]

ARPANET mail

Experimental email transfers between separate computer systems began shortly after the creation of the ARPANET in 1969.^[8] Ray Tomlinson is generally credited as having sent the first email across a network, initiating the use of the "@" sign to separate the names of the user and the user's machine in 1971, when he sent a message from one Digital Equipment Corporation DEC-10 computer to another DEC-10. The two machines were placed next to each other.^[12][45] Tomlinson's work was quickly adopted across the ARPANET, which significantly increased the popularity of email. Tomlinson is internationally known as the inventor of modern email.^[46]

Initially addresses were of the form, username@hostname^[47] but were extended to "username@host.domain" with the development of the Domain Name System (DNS).

As the influence of the ARPANET spread across academic communities, gateways were developed to pass mail to and from other networks such as CSNET, JANET, BITNET, X.400, and FidoNet. This often involved addresses such as:

hubhost!middlehost!edgehost!user@uucpgateway.somedomain.example.com

which routes mail to a user with a "bang path" address at a UUCP host.

References

External links

Look up email or outbox in Wiktionary, the free dictionary.

• IANA's list of standard header fields
• The History of Email is Dave Crocker's attempt at capturing the sequence of 'significant' occurrences in the evolution of email; a collaborative effort that also cites this page.
• The History of Electronic Mail is a personal memoir by the implementer of an early email system
• A Look at the Origins of Network Email is a short, yet vivid recap of the key historical facts
• Business E-Mail Compromise - An Emerging Global Threat, FBI