Internet Draft: MDN profile for IMAP A. Melnikov
Document: draft-melnikov-imap-keywords-00.txt MessagingDirect
Expires: December 2002 J. Neystadt
Intended category: Informational Comverse
June 2002
Registration of common IMAP keywords
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. 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
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Internet-Drafts are draft documents valid for a maximum of six months
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A revised version of this draft document will be submitted to the RFC
editor as an Informational document. Discussion and suggestions for
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Copyright Notice
Copyright (C) The Internet Society (2002). All Rights Reserved.
0. To do list and open issues
Open issues are enclosed in << and >> through out this document.
This document is still very raw. Comments are encouraged.
<< Define a regular template?:
Purpose: ...
Private or Shared on a server: private/shared/both
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Is it an advisory keyword or may it cause an automatic action?
When/by whom the keyword is set/cleared: ...
>>
<<Define mutual exclusive $Work, $Personal (and $Spam)>>
<<Define special capabilities returned by cooperating servers?>>
Table of Contents
0. To do.........................................................1
1. Abstract......................................................2
2. Conventions Used in this Document.............................2
3. IMAP keyword registrations....................................3
3.1 $Forwarded....................................................3
3.2 $Important....................................................3
3.3 $ShouldReply..................................................4
3.4 $Spam.........................................................4
3.5 $Adult........................................................4
4. Security Considerations.......................................4
5. Other considerations..........................................4
6. Formal Syntax.................................................4
7. Acknowledgments...............................................5
8. References....................................................5
9. Author's Addresses............................................5
10. Full Copyright Statement......................................6
1. Abstract
The aim of this document is to document some common [IMAP4] keywords
for the purpose of improving interoperability between different IMAP
mail clients. The document both documents some keywords already in
use, as well as introduces several new ones.
2. Conventions Used in this Document
"C:" and "S:" in examples show lines sent by the client and server
respectively.
The keywords "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and "MAY" in
this document when typed in uppercase are to be interpreted as
defined in "Key words for use in RFCs to Indicate Requirement Levels"
[KEYWORDS].
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3. IMAP keyword registrations
3.1 $Forwarded
$Forwarded is used by several IMAP clients to specify that the
message was forwarded (either inline or as an attachment) to another
email address. This keyword is set by the mail client when it
successfully forwards the message to another email address.
3.2 $Important
[IMAP4] doesn't specify exact semantics of the \Flagged flag. It
suggests that it is upto a MUA to assign any special meaning to it.
Most intuitive meaning of \Flagged is probbably to mark that message
as important. However since the same user can use multiple MUAs from
different vendors, there are some MUAs that use it for different
purposes. In order to introduce a consistent "Important" mark a new
flag is required. This document defines a new keyword $Important for
this purpose.
The server that recognizes $Important SHOULD automatically set it on
a message injection if the root bodypart of that message contains the
header field "Importance" with the value "High". The server SHOULD
also set this keyword if the root body part contains either a header
field "Priority" with the value of "urgent" [HEADERS] or a header
field "X-Priority" with the value "1" or "2".
Note that a header field value comparison MUST be done after removing
RFC 822 comments (see section 3.2.3 of [RFC 2822]). For example, the
"X-Priority" header field with the value "1 (Highest)" and "1" MUST
be treated the same way.
<<Describe how client should display that: use described header
fields if the $Important keyword is not set. The keyword override
header fields.>>
<<Added mutual exclusive $Important/$Normal/$Unimportant, so that we
can override the meaning prescribed by headers?>>
<<Separate Importance from Priority? I don't see much difference,
except for Priority controlling delivery speed, that most MTAs
probably ignore anyway. Define separate flags?>>
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3.3 $ShouldReply
The user may mark a message with this keyword to specify that the
message requires a reply. One possible use of this keyword is to
group in some way all messages having this keyword. Another possible
use would be to periodically pop up a dialog requesting the user to
send a reply. When a reply to this message is sent, the mail client
MUST remove this keyword and MUST set the \Answered flag.
3.4 $Spam
The user may choose to mark a message as containing Spam. This
keyword can be used to mark, group or hide offensive messages.
3.5 $Adult
The user may choose to mark a message as being inappropriate for
minors. A mail client equipped with parental control functionality
MUST use this keyword to prevent the message from being displayed to
a minor user. If recognized by the server, this keyword SHOULD be
implemented as a shared keyword.
4. Security Considerations
<< Danger of an automatic initiation of an action based on $Spam or
$Adult keywords >>
5. Other considerations
<< ANNOTATE extension is supposed to replace this. Describe how to
map the keywords defined in this document to ANNOTATE attributes. >>
6. Formal Syntax
The following syntax specification uses the augmented Backus-Naur
Form (BNF) notation as specified in [RFC-822] as modified by [IMAP4].
Non-terminals referenced but not defined below are as defined by
[IMAP4].
Except as noted otherwise, all alphabetic characters are case-
insensitive. The use of upper or lower case characters to define
token strings is for editorial clarity only. Implementations MUST
accept these strings in a case-insensitive fashion.
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flag_keyword ::= "$Forwarded" / "$Important" / "$ShouldReply" /
"$Spam" / "$Adult" / other_keywords
other_keywords ::= atom
7. Acknowledgments
The creation of this document was prompted by one of many discussions
on the IMAP mailing list.
8. References
[KEYWORDS] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997.
[IMAP4] Crispin, M., "Internet Message Access Protocol - Version
4rev1", RFC 2060, University of Washington, December 1996.
[RFC 2822] Resnick, P., "Internet Message Format", RFC 2822, QUALCOMM
Incorporated, April 2001.
[] Palme, J., "Common Internet Message Headers", RFC 2076,
Stockholm University/KTH, February 1997.
[ANNOTATION] Gellens, R., Daboo, C., "IMAP ANNOTATE Extension", work
in progress, <http://www.ietf.org/internet-drafts/draft-ietf-imapext-
annotate-xx.txt>
9. Author's Addresses
Alexey Melnikov
ACI Worldwide/MessagingDirect
Address: 22 The Quadrant, Richmond, Surrey, United Kingdom, TW9 1BP
Phone: +44 20 8332 4508
Email: mel@messagingdirect.com
John Neystadt
Comverse Technology
Address: Habarzel 29, Ramat Hahayal, Tel-Aviv, Israel, 69710
Phone: +972-3-645-4185
Email: john@comverse.com
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10. Full Copyright Statement
Copyright (C) The Internet Society (2002). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
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kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
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followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
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Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
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