RFC 1854 (rfc1854) - Page 2 of 7
SMTP Service Extension for Command Pipelining
Alternative Format: Original Text Document
RFC 1854 SMTP Pipelining October 1995 until some intermediate point in the SMTP dialogue. When this is done material read from the TCP connection and kept in process buffers can be lost. (2) Flushing the TCP input buffer when an SMTP command fails. SMTP commands often fail but there is no reason to flush the TCP input buffer when this happens. Nevertheless, some SMTP servers do this. (3) Improper processing and promulgation of SMTP command failures. For example, some SMTP servers will refuse to accept a DATA command if the last RCPT TO command fails, paying no attention to the success or failure of prior RCPT TO command results. Other servers will accept a DATA command even when all previous RCPT TO commands have failed. Although it is possible to accommodate this sort of behavior in a client that employs command pipelining, it does complicate the construction of the client unnecessarily. This memo uses the mechanism described in [2] to define an extension to the SMTP service whereby an SMTP server can declare that it is capable of handling pipelined commands. The SMTP client can then check for this declaration and use pipelining only when the server declares itself capable of handling it. 1. Framework for the Command Pipelining Extension The Command Pipelining extension is defined as follows: (1) the name of the SMTP service extension is Pipelining; (2) the EHLO keyword value associated with the extension is PIPELINING; (3) no parameter is used with the PIPELINING EHLO keyword; (4) no additional parameters are added to either the MAIL FROM or RCPT TO commands. (5) no additional SMTP verbs are defined by this extension; and, (6) the next section specifies how support for the extension affects the behavior of a server and client SMTP. Freed & Cargille Standards Track
