RFC5321bis Document Shepherd Write-up
# Document Shepherd Write-Up for Group Documents
*This version of the template is dated 4 July 2022.*
Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.
Note that some numbered items contain multiple related questions; please be sure
to answer all of them.
## Document History
1. Does the working group (WG) consensus represent the strong concurrence of a
few individuals, with others being silent, or did it reach broad agreement?
The EMAILCORE working group’s charter was to perform a "limited review and
revision" of documents that describe a widely installed and used protocol.
Participation in the working group was generally limited to a
dozen or so individuals, owing in large part to the group’s work being
focused on revising fifteen year old documents that are themselves
forth-generation revisions of originals first published in 1982.
When reviewing this document, it is strongly suggested that you refer to:
https://author-tools.ietf.org/iddiff?url1=rfc5321&url2=draft-ietf-emailcore-rfc5321bis
Also, please read <https://datatracker.ietf.org/doc/draft-ietf-emailcore-as/> for various
security considerations related to email systems.
2. Was there controversy about particular points, or were there decisions where
the consensus was particularly rough?
No controversy about particular points, although quite a lot of
polite, thorough and sometimes slow discussion about the details of
specific sections. Also the WG spent quite a bit of time updating
(modernizing) IANA registration policies for various registries, as
well as reviewing whether particular features were still in use. In
the latter case, the WG erred on the side of caution to keep some less
widely used options in order not to break implementations currently
complying with RFC 5321.
Extensive SecDir and DnsDir reviews uncovered some smaller issues
(like outdated text or some unclear things), but -38 is believed
to address all major (and many minor) comments, and it reflects
WG consensus on the rest of proposed suggestions.
One possible remaining issue is whether any text about TLS needs
to be specified (note that STARTTLS is an extension specified in
a separate RFC and most of discussions of its use are in
draft-ietf-emailcore-as).
3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
so, please summarize the areas of conflict in separate email messages to the
responsible Area Director. (It should be in a separate email because this
questionnaire is publicly available.)
No known threats of appeal.
4. For protocol documents, are there existing implementations of the contents
of the document? Have a significant number of potential implementers indicated
plans to implement? Are any existing implementations reported somewhere,
either in the document itself (as [RFC 7942][3] recommends) or elsewhere
(where)?
There are countless implementations of the contents of the document, including
open source and proprietary clients and server, as well as libraries in many
programming languages.
## Additional Reviews
5. Do the contents of this document closely interact with technologies in other
IETF working groups or external organizations, and would it therefore benefit
from their review? Have those reviews occurred? If yes, describe which
reviews took place.
While SMTP is in wide use, both inside and outside
the IETF, review beyond those who participated in the WG was not considered
necessary. We had a good cross-section of people in the WG, and the task was
to preserve compatibility with all existing implementations.
SecDir, DnsDir and GenArt reviews were helpful in finding some outdated text
in the document. Some proposed changes are out of scope due to the WG Charter.
6. Describe how the document meets any required formal expert review criteria,
such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
No MIBs, YANG, new media type, or URI type specifications in this document.
7. If the document contains a YANG module, has the final version of the module
been checked with any of the [recommended validation tools][4] for syntax and
formatting validation? If there are any resulting errors or warnings, what is
the justification for not fixing them at this time? Does the YANG module
comply with the Network Management Datastore Architecture (NMDA) as specified
in [RFC 8342][5]?
The document does not contain a YANG module.
8. Describe reviews and automated checks performed to validate sections of the
final version of the document written in a formal language, such as XML code,
BNF rules, MIB definitions, CBOR's CDDL, etc.
The ABNF rules in the document have undergone thorough manual review by members
of the working group during this cycle, as well as during each publishing cycle
for previous revisions of this document (RFCs 821, 2821, and 5321).
Alexey Melnikov used a formal ABNF checker on ABNF extracted from -29.
Some small errors were found and they were fixed in -30.
There were no further ABNF changes between version 30 and 38.
## Document Shepherd Checks
9. Based on the shepherd's review of the document, is it their opinion that this
document is needed, clearly written, complete, correctly designed, and ready
to be handed off to the responsible Area Director?
Yes.
10. Several IETF Areas have assembled [lists of common issues that their
reviewers encounter][6]. For which areas have such issues been identified
and addressed? For which does this still need to happen in subsequent
Reviews?
There was an extensive discussion on the list about the use of the terms
"ASCII" and "US-ASCII". The experts seemed satisfied that the use of the
terms in this document is reasonable and correct. No other "common issues"
appeared problematic.
11. What type of RFC publication is being requested on the IETF stream ([Best
Current Practice][12], [Proposed Standard, Internet Standard][13],
[Informational, Experimental or Historic][14])? Why is this the proper type
of RFC? Do all Datatracker state attributes correctly reflect this intent?
The type of RFC publication being requested is Internet Standard. RFC 2026,
Section 4.1.3, Internet Standard, reads:
A specification for which significant implementation and successful
operational experience has been obtained may be elevated to the
Internet Standard level. An Internet Standard (which may simply be
referred to as a Standard) is characterized by a high degree of
technical maturity and by a generally held belief that the specified
protocol or service provides significant benefit to the Internet
community.
This document (5321bis) updates the definition of the SMTP protocol
used for sending "electronic mail" messages, its extensibility
and mentions some very common SMTP extensions (mostly as examples
of extensibility). This protocol has significant implementation and
successful operational experience. Futhermore, the fact that electronic
mail in the form of mailing lists serves as the foundation for much of
the work that IETF Working Groups accomplish seems to stand as the primary
evidence that electronic mail provides a significant benefit to the Internet
community, to say nothing of electronic mail's role as a communication tool
for individuals across the globe.
12. Have reasonable efforts been made to remind all authors of the intellectual
property rights (IPR) disclosure obligations described in [BCP 79][7]? To the
best of your knowledge, have all required disclosures been filed? If not,
explain why. If yes, summarize any relevant discussion, including links to
publicly-available messages when applicable.
All reasonable efforts have been made to remind authors of IPR disclosure
obligations. No required disclosures exist to be filed.
Do note that the BCP *78* template used in this document is the pre-5378
template. Given the age of some of the text in this document, it is impossible
to assure that all rights have been obtained to be able to claim full
permission.
13. Has each author, editor, and contributor shown their willingness to be
listed as such? If the total number of authors and editors on the front page
is greater than five, please provide a justification.
Yes.
14. Document any remaining I-D nits in this document. Simply running the
[idnits][8] tool is not enough; please review the ["Content Guidelines" on
authors.ietf.org][15]. (Also note that the current idnits tool generates
some incorrect warnings; a rewrite is underway.)
ID-Nits checker complains about a few things, which are either in RFC Editor notes
that will be removed or is mistaken:
** The abstract seems to contain references ([55]), which it shouldn't.
Please replace those with straight textual mentions of the documents in
question.
-- The draft header indicates that this document obsoletes RFC7504, but the
abstract doesn't seem to mention this, which it should.
-- The draft header indicates that this document obsoletes RFC7505, but the
abstract doesn't seem to mention this, which it should.
-- The draft header indicates that this document obsoletes RFC1846, but the
abstract doesn't seem to mention this, which it should.
ID-Nits also complains:
== There are 2 instances of lines with non-RFC2606-compliant FQDNs in the
document.
which is as expected in a bis document.
There is a warning about weird spacing. This is in regards to an example
that is using such spacing deliberately.
ID-Nits is reporting duplicated references, but it is mistaken:
-- Duplicate reference: RFC20, mentioned in '5', was also mentioned in '4'.
-- Duplicate reference: RFC1035, mentioned in '8', was also mentioned in
'7'.
-- Duplicate reference: RFC5321, mentioned in '64', was also mentioned in
'55'.
-- Duplicate reference: RFC5321, mentioned in '66', was also mentioned in
'64'.
(In particular, [64] and [66] are errata, not RFC 5321)
ID-Nits is correct that [60] is not referenced.
15. Should any informative references be normative or vice-versa? See the [IESG
Statement on Normative and Informative References][16].
Normative and Informative references are properly classified as such.
16. List any normative references that are not freely available to anyone. Did
the community have sufficient access to review any such normative
References?
ANSI X3.4-1968 is not officially available freely, but it is findable easily
on the web.
17. Are there any normative downward references (see [RFC 3967][9] and [BCP
97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
list them.
There is a normative reference to RFC 821 in regards to use of features
that were removed in this revision of SMTP.
18. Are there normative references to documents that are not ready to be
submitted to the IESG for publication or are otherwise in an unclear state?
If so, what is the plan for their completion?
There are no normative references to documents that are not ready to be
submitted to the IESG for publication or are otherwise in an unclear state.
19. Will publication of this document change the status of any existing RFCs? If
so, does the Datatracker metadata correctly reflect this and are those RFCs
listed on the title page, in the abstract, and discussed in the
introduction? If not, explain why and point to the part of the document
where the relationship of this document to these other RFCs is discussed.
This document is intended to obsolete RFC 5321, RFC 1846, RFC 7504 and RFC 7505,
and is noted as such.
20. Describe the document shepherd's review of the IANA considerations section,
especially with regard to its consistency with the body of the document.
Confirm that all aspects of the document requiring IANA assignments are
associated with the appropriate reservations in IANA registries. Confirm
that any referenced IANA registries have been clearly identified. Confirm
that each newly created IANA registry specifies its initial contents,
allocations procedures, and a reasonable name (see [RFC 8126][11]).
The IANA Considerations section has significant updates to bring the document
in line with modern IETF practices (in particular to make registration
of SMTP extensions easier, as well as to clarify the registration template).
Any referenced IANA registries have been clearly identified.
No new registries are created by this document, however some missing
values were identified in existing registries. For example see Section 8.3.3.3
Registration procedures for various existing registries were updated
or clarified. In some cases extra registration fields were added.
The document also contains instructions for IANA about reorganizing
the Mail Parameters Registry Group.
21. List any new IANA registries that require Designated Expert Review for
future allocations. Are the instructions to the Designated Expert clear?
Please include suggestions of designated experts, if appropriate.
None. See the answer to 20) for more details.