This memo defines a MIME content-type that may be used by a message transfer agent (MTA) or electronic mail gateway to report the result of an attempt to deliver a message to one or more recipients. [STANDARDS-TRACK]| IETF Datatracker
There currently is not a standard mechanism for the reporting of mail system errors except for the limited set offered by SMTP and the system specific text descriptions sent in mail messages. There is a pressing need for a rich machine readable status code for use in delivery status notifications [DSN]. This document proposes a new set of status codes for this purpose. [STANDARDS-TRACK]| IETF Datatracker
This memo describes a low cost, deterministic means for messages to be identified as submissions, and specifies what actions are to be taken by a submission server. [STANDARDS-TRACK]| IETF Datatracker
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]| IETF Datatracker