Electronic mail

Electronic mail, often abbreviated to e-mail, email, or simply mail, is a store-and-forward method of writing, sending, receiving and saving messages over electronic communication systems. The term "e-mail" (as a noun or verb) applies to the Internet e-mail system based on the Simple Mail Transfer Protocol, to network systems based on other protocols and to various mainframe, minicomputer or intranet systems allowing users within one organization to send messages to each other in support of workgroup collaboration. Intranet systems may be based on proprietary protocols supported by a particular systems vendor, or on the same protocols used on public networks. E-mail is often used to deliver bulk unsolicited messages, or "spam", but filter programs exist which can automatically block, quarantine or delete some or most of these, depending on the situation.

ORIGIN

E-mail predates the inception of the Internet, and was in fact a crucial tool in creating the Internet. MIT first demonstrated the Compatible Time-Sharing System (CTSS) in 1961. It allowed multiple users to log into the IBM 7094 from remote dial-up terminals, and to store files online on disk. This new ability encouraged users to share information in new ways like the online yellow pages. E-mail started in 1965 as a way for multiple users of a time-sharing mainframe computer to communicate. Although the exact history is murky, among the first systems to have such a facility were SDC's Q32 and MIT's CTSS.

E-mail was quickly extended to become network e-mail, allowing users to pass messages between different computers by at least 1966 (it is possible the SAGE system had something similar some time before).

The ARPANET computer network made a large contribution to the development of e-mail. There is one report that indicates experimental inter-system e-mail transfers on it shortly after its creation in 1969. Ray Tomlinson initiated the use of the @ sign to separate the names of the user and their machine in 1971. The ARPANET significantly increased the popularity of e-mail, and it became the killer app of the ARPANET.