RFC 2034 Proposed Standard Transport

SMTP Service Extension for Returning Enhanced Error Codes

This memo defines an extension to the SMTP service [RFC-821, RFC-1869] whereby an SMTP server augments its responses with the enhanced mail system status codes defined in RFC 1893. [STANDARDS-TRACK]

Status: Proposed Standard. On the standards track and stable enough to implement against. Most of the email stack stays at this level permanently.
Published: October 1996
Authors: N. Freed
Read it: rfc-editor.org · DOI

Normative requirements

Every sentence in this RFC carrying an RFC 2119 keyword, with the section it came from. 1 must, 0 should, 0 may.

Filter the requirements

5 Status Codes and Negotiation

MUST NOTIt MUST NOT be taken as a license for future SMTP extensions to dramatically change the nature of SMTP client-server interaction without proper announcement from the server and a corresponding enabling command from the client.

Every current email RFC