ESMTP

Extended SMTP (ESMTP), sometimes referred to as Enhanced SMTP, is a definition of protocol extensions to the Simple Mail Transfer Protocol standard. The extension format was defined in RFC 1869 in 1995.RFC 1869 established a structure for all existing and future extensions, to produce a consistent and manageable means by which ESMTP clients and servers can be identified and ESMTP servers can indicate supported extensions to connected clients.
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<messaging, protocol> Extended SMTP. Initially defined in RFC 1869 and extended thereafter.
See also ETRN.
(1997-11-21)