EAI: Simplified POP/IMAP downgrading
draft-ietf-eai-simpledowngrade-05
The information below is for an old version of the document |
Document |
Type |
|
Active Internet-Draft (eai WG)
|
|
Author |
|
Arnt Gulbrandsen
|
|
Last updated |
|
2012-06-11
|
|
Stream |
|
IETF
|
|
Intended RFC status |
|
Proposed Standard
|
|
Formats |
|
pdf
htmlized (tools)
htmlized
bibtex
|
|
Reviews |
|
|
Stream |
WG state
|
|
WG Document
|
|
Document shepherd |
|
None
|
IESG |
IESG state |
|
AD is watching
|
|
Consensus Boilerplate |
|
Unknown
|
|
Telechat date |
|
|
|
Responsible AD |
|
Pete Resnick
|
|
Send notices to |
|
eai-chairs@tools.ietf.org, draft-ietf-eai-simpledowngrade@tools.ietf.org
|
Network Working Group Arnt Gulbrandsen
Internet-Draft June 2012
Intended Status: Proposed Standard
Updates: 3501
EAI: Simplified POP/IMAP downgrading
draft-ietf-eai-simpledowngrade-05.txt
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79.
Copyright (c) 2012 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
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
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.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-
Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft expires in November 2012.
Gulbrandsen Expires December 2012 [Page 1]
Internet-draft June 2012
Abstract
This document specifies a method for IMAP and POP servers to serve
internationalized messages to conventional clients. The specification
is simple, easy to implement and provides only rudimentary results.
1. Overview
It may happen that a conventional IMAP or POP client opens a mailbox
containing internationalized messages, or even attempt to read
internationalized messages, for instance when a user has both
internationalized and conventional MUAs.
Some operations cannot be performed by conventional clients. Most
importantly, one or more addresses on an internationalized message
are not valid according to the specifications the client uses, so
address-based operations are not possible. This includes displaying
the addresses, replying, and most types of address-based signature or
security processing.
Still, the sender's name, the message subject, body text and
attachments can easily be displayed, so a helpful IMAP/POP server may
prefer to provide access to what it can rather than hide the message
entirely.
This document specifies a way to present such messages to the client.
It values simplicity of implementation over fidelity of
representation, since implementing a high-fidelity downgrade
algorithm is likely more work than implementing proper support for
[RFC5721] and/or [RFC5738].
The server is assumed to be internationalized internally, and to
store messages internationalized messages natively. When it needs to
present an internationalized message to a conventional client, it
synthesizes a conventional message containing most of the information
and presents that (the "synthetic message").
2. Information preserved and lost
The synthetic message is intended to convey the most important
information to the user. Where information is lost, the user should
see the message as incomplete rather than modified.
The synthetic message is not intended to convey any information to
the client software.
Gulbrandsen Expires December 2012 [Page 2]
Internet-draft June 2012
Upper case in examples represents non-ASCII. example.com is a plain
domain, EXAMPLE.com represents a non-ASCII .com domain.
2.1 Email addresses
Each internationalized email address in the header fields listed
below is replaced with an invalid email address whose display-name
tells the user what happened.
The format of the display-name is explicitly unspecified. Anything
which tells the user what happened is good. Anything which produces
an email address which might belong to someone else is bad.
Given an internationalized address "Fred Foo <fred@EXAMPLE.com>", an
implementation may choose to render it e.g. as these examples:
"fred@EXAMPLE.com" <invalid@internationalized-address.invalid>
Fred Foo <invalid@internationalized.invalid>
Show full document text