The specification for enhanced mail system enhanced status codes, RFC
3463, establishes a new code model and lists a collection of status
codes. While it anticipated that more codes would be added over
time, it did not provide an explicit mechanism for registering and
tracking those codes. This document specifies an IANA registry for
mail system enhanced status codes, and initializes that registry with
the codes so far established in published standards-track documents,
as well as other codes that have become established in the industry.
Working Group Summary
This document has been reviewed on the ietf-smtp mailing list.
There have been several comments on details, which have largely
been incorporated, and substantial revisions from the first draft
to this one. No objection to the effort has been made; the
authors have been commended for undertaking the effort.
The document has been reviewed by the mailing list and the document
shepherd. The specific codes described here document existing
practice, except for the newly defined codes that are concerned
with resolving conflicts between multiple usages of codepoints
in present usage. This was reviewed for the IESG by Chris
Note to RFC Editor
In Section 2.2, delete the following:
The procedures from [RFC4020] may be followed to pre-allocate an
Enhanced Status Code before final publication of an internet draft.
In section 2.3, please replace "responsible party" with "change
In Section 5.1, delete the following:
[RFC4020] Kompella, K. and A. Zinin, "Early IANA Allocation of
Standards Track Code Points", BCP 100, RFC 4020,