< messaging > (Usually "e-mail address", rarely "e-dress", "e-ddress") The string used to specify the source or destination of an electronic mail message. E.g. "john@doc.acme.ac.uk".
The RFC 822 standard is probably the most widely used on the Internet though X.400 is also in use in Europe and Canada. UUCP -style ( bang path ) addresses or other kinds of source route became virtually extinct in the 1990s.
In the example above, "john" is the local part which is the name of a mailbox on the destination computer. If the sender and recipient use the same computer, or the same LAN , for electronic mail then the local part is usually all that is required.
If they use different computers, e.g. they work at different companies or use different Internet service providers , then the "host part", e.g. "sales.acme.com" must be appended after an "@". This usually takes the form of a fully qualified domain name or, within a large organisation, it may be just the hostname part, e.g. "sales". The destination computer named by the host part is often a server of some kind rather than an individual's workstation or PC . The user's mail is stored on the server and read later via client mail software running on the user's computer.
Large organisations, such as universities will often set up a global alias directory which maps a simple user name such as "jsmith" to an address which contains more information such as "jsmith@london.bigcomp.co.uk". This hides the detailed knowledge of where the message will be delivered from the sender, making it much easier to redirect mail if a user leaves or moves to a different computer for example.
(1996-10-22)