Internet DRAFT - draft-klensin-email-core-as
draft-klensin-email-core-as
Network Working Group J. Klensin, Ed.
Internet-Draft March 30, 2020
Intended status: Standards Track
Expires: October 1, 2020
Applicability Statement for IETF Core Email Protocols
draft-klensin-email-core-as-00
Abstract
Electronic mail is one of the oldest Internet applications that is
still in very active use. While the basic protocols and formats for
mail transport and message formats have evolved slowly over the
years, events and thinking in more recent years have supplemented
those core protocols with additional features and suggestions for
their use. This Applicability Statement describes the relationship
among many of those protocols and provides guidance and makes
recommendations for the use of features of the core protocols.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on October 1, 2020.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Applicability of Some SMTP Provisions . . . . . . . . . . . . 3
3. Applicability of Message Format Provisions . . . . . . . . . 3
4. MIME and Its Implications . . . . . . . . . . . . . . . . . . 3
5. Other Stuff . . . . . . . . . . . . . . . . . . . . . . . . . 4
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
8. Security Considerations . . . . . . . . . . . . . . . . . . . 4
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
9.1. Normative References . . . . . . . . . . . . . . . . . . 4
9.2. Informative References . . . . . . . . . . . . . . . . . 5
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
In its current form, this draft is a placeholder and beginning of an
outline for the Applicability Statement that has been discussed as a
complement for proposed revisions of the base protocol specifications
for SMTP [RFC5321] (being revised as ID.RFC5321bis [ID.RFC5321bis])
and Internet Message Format [RFC5322] (being revised as ID.RFC5322bis
[ID.RFC5322bis]). Among other things, it is expected to capture
topics that a potential WG concludes are important but that should
not become part of those core documents.
As discussed in RFC 2026 [RFC2026],
"An Applicability Statement specifies how, and under what
circumstances, one or more TSs may be applied to support a
particular Internet capability."
That form of a standards track document is appropriate because one of
the roles of such a document is to explain the relationship among
technical specification, describe how they are used together, and
make statements about what is "required, recommended, or elective".
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119] and
RFC 8174 [RFC8174].
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2. Applicability of Some SMTP Provisions
Over the years since RFC 5321 was published in October 2008, usage of
SMTP has evolved, machines and network speeds have increased, and the
frequency with which SMTP senders and receivers have to be prepared
to deal with systems that are disconnected from the Internet for long
periods or that require many hops to reach has decreased. During the
same period, the IETF has become much more sensitive to privacy and
security issues and the need to be more resistant or robust against
spam and other attacks. In addition SMTP (and Message Format)
extensions have been introduced that are expected to evolve the
Internet's mail system to better accommodate environments in which
Basic Latin Script is not the norm.
This section describes adjustments that may be appropriate for SMTP
under various circumstances and discusses the applicability of other
protocols that represent newer work or that are intended to deal with
relatively newer issues.
[[CREF1: ... Actual content to be supplied after WG consideration.
]]
3. Applicability of Message Format Provisions
Placeholder:
I am not sure what, if anything, goes here. If nothing does, we drop
the section.
[[CREF2: ... Actual content to be supplied after WG consideration.]]
4. MIME and Its Implications
When the work leading to the original version of the MIME
specification was completed in 1992 [RFC1341], the intention was that
it be kept separate from the specification for basic mail headers in
RFC 822 [RFC0822]. That plan was carried forward into RFC 822's
successors, RFC 2822 [RFC2822] and RFC 5322 [RFC5322]. The decision
to do so was different from the one made for SMTP, for which the core
specification was changed to allow for the extension mechanism
[RFC1425] which was then incorporated into RFC 5321 and its
predecessor [RFC2821].
Various uses of MIME have become nearly ubiquitous in contemporary
email while others may have fallen into disuse or been repurposed
from the intent of their original design.
It may be appropriate to make some clear statements about the
applicability of MIME and its features.
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5. Other Stuff
It is fairly clear that there will be things that do not fit into the
sections outlined above. As one example, if the IETF wants to say
something specific about signatures over headers or what (non-trace)
headers may reasonably be altered in transit, that may be more
appropriate to other sections than to any of the three suggested
above.
6. Acknowledgments
... To be supplied...
[[CREF3: But don't forget to mention the discussions on the SMTP list
of the reasons for this document in the last half of 2019. ]]
7. IANA Considerations
This memo includes no requests to or actions for IANA. The IANA
registries associated with the protocol specifications it references
are specified in their respective documents.
8. Security Considerations
All drafts are required to have a security considerations section and
this one eventually will.
... To be supplied ...
9. References
9.1. Normative References
[RFC2026] Bradner, S., "The Internet Standards Process -- Revision
3", BCP 9, RFC 2026, DOI 10.17487/RFC2026, October 1996,
<https://www.rfc-editor.org/info/rfc2026>.
[RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part One: Format of Internet Message
Bodies", RFC 2045, DOI 10.17487/RFC2045, November 1996,
<https://www.rfc-editor.org/info/rfc2045>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
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[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
9.2. Informative References
[ID.RFC5321bis]
Klensin, J., "Simple Mail Transfer Protocol", December
2019, <https://datatracker.ietf.org/doc/draft-klensin-
rfc5321bis/>.
[ID.RFC5322bis]
Resnick, P., "Internet Message Format", December 2019,
<https://datatracker.ietf.org/doc/draft-resnick-
rfc5322bis/>.
[RFC0822] Crocker, D., "STANDARD FOR THE FORMAT OF ARPA INTERNET
TEXT MESSAGES", STD 11, RFC 822, DOI 10.17487/RFC0822,
August 1982, <https://www.rfc-editor.org/info/rfc822>.
[RFC1341] Borenstein, N. and N. Freed, "MIME (Multipurpose Internet
Mail Extensions): Mechanisms for Specifying and Describing
the Format of Internet Message Bodies", RFC 1341,
DOI 10.17487/RFC1341, June 1992,
<https://www.rfc-editor.org/info/rfc1341>.
[RFC1425] Klensin, J., Freed, N., Ed., Rose, M., Stefferud, E., and
D. Crocker, "SMTP Service Extensions", February 1993,
<https://www.rfc-editor.org/info/rfc1425>.
[RFC2821] Klensin, J., Ed., "Simple Mail Transfer Protocol",
RFC 2821, DOI 10.17487/RFC2821, April 2001,
<https://www.rfc-editor.org/info/rfc2821>.
[RFC2822] Resnick, P., Ed., "Internet Message Format", RFC 2822,
DOI 10.17487/RFC2822, April 2001,
<https://www.rfc-editor.org/info/rfc2822>.
[RFC5321] Klensin, J., "Simple Mail Transfer Protocol", RFC 5321,
DOI 10.17487/RFC5321, October 2008,
<https://www.rfc-editor.org/info/rfc5321>.
[RFC5322] Resnick, P., Ed., "Internet Message Format", RFC 5322,
DOI 10.17487/RFC5322, October 2008,
<https://www.rfc-editor.org/info/rfc5322>.
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Author's Address
John C Klensin (editor)
1770 Massachusetts Ave, Ste 322
Cambridge, MA 02140
USA
Phone: +1 617 245 1457
Email: john-ietf@jck.com
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