users.
sender-SMTP process
A process which transfers mail in cooperation with a receiver-SMTP
process. A local language may be used in the user interface
command/reply dialogue. The sender-SMTP initiates the transport
service connection. It initiates SMTP commands, receives replies,
and governs the transfer of mail.
session
The set of exchanges that occur while the transmission channel is
open.
transaction
The set of exchanges required for one message to be transmitted
for one or more recipients.
transmission channel
A full-duplex communication path between a sender-SMTP and a
receiver-SMTP for the exchange of commands, replies, and mail
text.
transport service
Any reliable stream-oriented data communication services. For
example, NCP, TCP, NITS.
August 1982 RFC821
Simple Mail Transfer Protocol
user
A human being (or a process on behalf of a human being) wishing to
obtain mail transfer service. In addition, a recipient of
computer mail.
word
A sequence of printing characters.
<CRLF>
The characters carriage return and line feed (in that order).
<SP>
The space character.
RFC821 August 1982
Simple Mail Transfer Protocol
REFERENCES
[1] ASCII
ASCII, "USA Code for Information Interchange", United States of
America Standards Institute, X3.4, 1968. Also in: Feinler, E.
and J. Postel, eds., "ARPANET Protocol Handbook", NIC 7104, for
the Defense Communications Agency by SRI International, Menlo
Park, California, Revised January 1978.
[2] RFC822
Crocker, D., "Standard for the Format of ARPA Internet Text
Messages," RFC822, Department of Electrical Engineering,
University of Delaware, August 1982.
[3] TCP
Postel, J., ed., "Transmission Control Protocol - DARPA Internet
Program Protocol Specification", RFC793, USC/Information Sciences
Institute, NTIS AD Number A111091, September 1981. Also in:
Feinler, E. and J. Postel, eds., "Internet Protocol Transition
Workbook", SRI International, Menlo Park, California, March 1982.
[4] NCP
McKenzie,A., "Host/Host Protocol for the ARPA Network", NIC 8246,
January 1972. Also in: Feinler, E. and J. Postel, eds., "ARPANET
Protocol Handbook", NIC 7104, for the Defense Communications
Agency by SRI International, Menlo Park, California, Revised
January 1978.
[5] Initial Connection Protocol
Postel, J., "Official Initial Connection Protocol", NIC 7101,
11 June 1971. Also in: Feinler, E. and J. Postel, eds., "ARPANET
Protocol Handbook", NIC 7104, for the Defense Communications
Agency by SRI International, Menlo Park, California, Revised
January 1978.
[6] NITS
PSS/SG3, "A Network Independent Transport Service", Study Group 3,
The Post Office PSS Users Group, February 1980. Available from
the DCPU, National Physical Laboratory, Teddington, UK.
August 1982 RFC821
Simple Mail Transfer Protocol
[7] X.25
CCITT, "Recommendation X.25 - Interface Between Data Terminal
Equipment (DTE) and Data Circuit-terminating Equipment (DCE) for
Terminals Operating in the Packet Mode on Public Data Networks,"
CCITT Orange Book, Vol. VIII.2, International Telephone and
Telegraph Consultative Committee, Geneva, 1976.