RFC 2033 (rfc2033) - Page 1 of 7
Local Mail Transfer Protocol
Alternative Format: Original Text Document
Network Working Group J. Myers
Request for Comments: 2033 Carnegie Mellon
Category: Informational October 1996
Local Mail Transfer Protocol
Status of this Memo
This memo provides information for the Internet community. This memo
does not specify an Internet standard of any kind. Distribution of
this memo is unlimited.
1. Abstract
SMTP [SMTP] [HOST-REQ] and its service extensions [ESMTP] provide a
mechanism for transferring mail reliably and efficiently. The design
of the SMTP protocol effectively requires the server to manage a mail
delivery queue.
In some limited circumstances, outside the area of mail exchange
between independent hosts on public networks, it is desirable to
implement a system where a mail receiver does not manage a queue.
This document describes the LMTP protocol for transporting mail into
such systems.
Although LMTP is an alternative protocol to ESMTP, it uses (with a
few changes) the syntax and semantics of ESMTP. This design permits
LMTP to utilize the extensions defined for ESMTP. LMTP should be
used only by specific prior arrangement and configuration, and it
MUST NOT be used on TCP port 25.
Table of Contents
1. Abstract ................................................ 1
2. Conventions Used in this Document ....................... 2
3. Introduction and Overview ............................... 2
4. The LMTP protocol ....................................... 3
4.1. The LHLO, HELO and EHLO commands ........................ 4
4.2. The DATA command ........................................ 4
4.3. The BDAT command ........................................ 5
5. Implementation requirements ............................. 6
6. Acknowledgments ......................................... 6
7. References .............................................. 7
8. Security Considerations ................................. 7
9. Author's Address ........................................ 7
Myers Informational