metasystema.org
ObsoletedINTERNET STANDARDLegacy streamSTD10

RFC 821: Simple Mail Transfer Protocol

This RFC has been replaced. Do not implement against it for new work — it was formally obsoleted by RFC 2821.

Current document in this lineage: RFC 5321 — Simple Mail Transfer Protocol

In plain English — editorial summary, not part of the RFC

The objective of Simple Mail Transfer Protocol (SMTP) is to transfer mail reliably and efficiently. SMTP is independent of the particular transmission subsystem and requires only a reliable ordered data stream channel. Obsoletes RFC 788, 780, and 772.

Document record

Document ID
RFC821
Published
August 1982
Authors
J. Postel
Status
INTERNET STANDARD
Stream
Legacy
Area
—
Pages
72
Also known as
STD10
Obsoletes:
RFC 788
Obsoleted by:
RFC 2821

Topics

Standards lineage

This document is one revision in a chain of 10 RFCs, each formally replacing the one before it.

  1. RFC 772 (1980)
  2. RFC 780 (1981)
  3. RFC 788 (1981)
  4. RFC 821 (1982)
  5. RFC 974 (1986)
  6. RFC 1425 (1993)
  7. RFC 1651 (1994)
  8. RFC 1869 (1995)
  9. RFC 2821 (2001)
  10. RFC 5321 (2008) ✓

Read the full history of Simple Mail Transfer Protocol →

Referenced by

One later RFC formally updates or obsoletes part of this document.

Related documents

Ranked automatically by shared keywords, IETF area and stream — not by editorial selection.

Also filed under

About this page

The document record above — title, authors, date, status, stream, area, relationships, DOI and errata — is imported verbatim from the public RFC Editor index. The “in plain English” section is editorial: written by The metasystema editorial team, not part of the RFC. Where the two differ, the RFC text governs.

Last checked against the RFC Editor index on . RFCs are never revised after publication; changes are issued as new documents.

Data sources · Editorial policy · Report a correction · What is an RFC?

canonical URL: /rfc/821-simple-mail-transfer-protocol