RFC 2034 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. These codes can then
be used to provide more informative explanations of error conditions,
especially in the context of the delivery status notifications format
defined in RFC 1894.
Copyright © 2004 Contact: Dave Wanta.