Sieve Working Group B. Leiba
Internet-Draft IBM T.J. Watson Research Center
Expires: April 19, 2007 M. Haardt
freenet.de AG
October 16, 2006
Sieve Notification Mechanism: mailto
draft-ietf-sieve-notify-mailto-01
Status of this Memo
By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79.
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 will expire on April 19, 2007.
Copyright Notice
Copyright (C) The Internet Society (2006).
Abstract
This document describes a profile of the Sieve extension for
notifications, to allow notifications to be sent by electronic mail.
Leiba & Haardt Expires April 19, 2007 [Page 1]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Conventions used in this document . . . . . . . . . . . . . 3
2. Definition . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Notify tag ":method" . . . . . . . . . . . . . . . . . . . . 4
2.2. Notify tag ":priority" . . . . . . . . . . . . . . . . . . . 4
2.3. Notify tag ":message" . . . . . . . . . . . . . . . . . . . 4
2.4. Other Definitions . . . . . . . . . . . . . . . . . . . . . 5
3. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4. Internationalization Considerations . . . . . . . . . . . . 9
5. Security Considerations . . . . . . . . . . . . . . . . . . 10
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . 11
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.1. Normative References . . . . . . . . . . . . . . . . . . . . 12
7.2. Non-Normative References . . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 13
Intellectual Property and Copyright Statements . . . . . . . 14
Leiba & Haardt Expires April 19, 2007 [Page 2]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
1. Introduction
1.1. Overview
The [Notify] extension to the [Sieve] mail filtering language is a
framework for providing notifications by employing URIs to specify
the notification mechanism. This document defines how [mailto] URIs
are used to generate notifications by e-mail.
1.2. Conventions used in this document
Conventions for notations are as in [Sieve] section 1.1, including
the use of [Kwds] and the use of [ABNF].
[[no abnf ref: We don't actually need the ABNF reference...]]
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 [Kwds].
Leiba & Haardt Expires April 19, 2007 [Page 3]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
2. Definition
The mailto mechanism results in the sending of a new email message (a
"notification message") to notify a recipient about a "triggering
message".
2.1. Notify tag ":method"
The mailto notification mechanism uses standard mailto URIs as
specified in [mailto]. URI headers with hname "from", "subject" and
"received" are ignored if specified; all other URI headers are
accepted.
[[Barry ignored: Should we ignore them, or should their presence be
an error?]]
[[Michael ignored: The mailto URI spec allows for either. I like
ignoring them more, because it fits into the picture of ignoring a
different sender for other message-generating actions, if it is
forbidden.]]
2.2. Notify tag ":priority"
The :priority tag has no special meaning for this notification
mechanism, and this specification puts no restriction on its use.
Implementations MAY use the value of :priority to set a priority or
importance indication on the notification message.
2.3. Notify tag ":message"
o Unless overridden by ":from", the "From:" header field and the
envelope sender of the notification message are set to the
envelope "to" field from the triggering message, as used by Sieve.
[[Barry from: It might be better in some cases for the
notification to "come from" the sender of the triggering message.
In other cases it might be better for all notifications to come
from the "mail system". I think we should define a way to specify
the behaviour here, perhaps with a new notify tag.]]
[[Michael from: Variables could perform both. Does that
suffice?]]
[[Barry sender: Should we also provide a mapping or setting for
the "Sender:" header field?]]
[[Michael sender: If that is required, the base spec should allow
it for all methods, like it offers ":from".]]
Leiba & Haardt Expires April 19, 2007 [Page 4]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
o The "To:" header field and the envelope recipient(s) of the
notification message are set to the address(es) specified in URI
(including any URI headers where the hname is "to").
[[Barry to: I'd like some way to specify that the To: header
should be retained from the triggering message. In fact, I'd like
a way to say that ALL headers be retained.]]
[[Michael to: Retaining the original "To:" field could easily
result in a loop. I think we need to define the focus of this
method: Generic SMTP message generation, or "just notifications"
over SMTP?]]
o The "Received:" field from the triggering message are retained in
the notification message, as these may help detect and prevent
mail loops.
o The "Subject:" field of the notification message contains the
value defined by the :message notify tag, as described in
[Notify]. If there is no :message tag, the subject is retained
from the triggering message. Note that Sieve [Variables] can be
used to advantage here, as shown in the example in Section 3.
o All other header fields of the notification message either are as
specified by URI headers, or have implementation-specific values;
their values are not defined here. It is suggested that the
implementation capitalizes the first letter of URI headers and
adds a space character after the colon between the mail header
name and value when adding URI headers to the message.
o If the mailto URI contains a "body" header, the value of that
header is used as the body of the notification message. If there
is no "body" header, the body of the notification message is
empty.
[[Barry body: I'd like some way to specify that the body contain
the body of the triggering message.]]
[[Michael body: Can variables do that? I don't know.]]
2.4. Other Definitions
Because the receipt of an email message is generating another email
message, implementations MUST take steps to avoid mail loops. The
notification message contains the "Received:" fields from the
triggering message to allow loop detection as described in [RFC2821],
section 6.2. The implementation MUST allow messages with empty
envelope senders to trigger notifications.
Leiba & Haardt Expires April 19, 2007 [Page 5]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
[[Barry loops: We should say more about this...]]
[[Michael loops: Ok now? Informal reference or normative? Could you
add it?]]
[[comment 1: Mailto URIs focus on the message, not its submission.
There is no way to specify envelope parameters, require encryption or
authentication. Sure enough there is more than SMTP, so mailto is
fine not to address this specific transport, but should we ever need
more, it can not be specified as URI header, because there is no room
in its namespace.]]
[[comment 2: Michael tried to get documentation on SMTP-SMS gateways,
but everybody operating one keeps the specification like a precious
secret. From experiments made some years ago, we know some gateways
ignore all messages with empty envelope senders, some do not
implement MIME and some ignore the body.]]
Leiba & Haardt Expires April 19, 2007 [Page 6]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
3. Examples
Triggering message (received by recipient@example.org):
Return-Path: <knitting-bounces@example.com>
Received: from mail.example.com by mail.example.org
for <recipient@example.org>; Wed, 7 Dec 2005 05:08:02 -0500
Received: from hobbies.example.com by mail.example.com
for <knitting@example.com>; Wed, 7 Dec 2005 02:00:26 -0800
Message-ID: <1234567.89ABCDEF@example.com>
Date: Wed, 07 Dec 2005 10:59:19 +0100
Precedence: list
List-Id: Knitting Mailing List <knitting.example.com>
Sender: knitting-bounces@example.com
Errors-To: knitting-bounces@example.com
From: "Jeff Smith" <jeff@hobbies.example.com>
To: "Knitting Mailing List" <knitting@example.com>
Subject: [Knitting] A new sweater
I just finished a great new sweater!
Sieve script (run on behalf of recipient@example.org):
require ["notify", "variables"];
if header :contains "list-id" "knitting.example.com" {
if header :matches "Subject" "[*] *" {
notify :method "mailto:0123456789@sms.example.net"
:message "From ${1} list: ${2}"
:priority "3";
}
}
Notification message:
Received: from mail.example.com by mail.example.org
for <recipient@example.org>; Wed, 7 Dec 2005 05:08:02 -0500
Received: from hobbies.example.com by mail.example.com
for <knitting@example.com>; Wed, 7 Dec 2005 02:00:26 -0800
Date: Wed, 7 Dec 2005 05:08:55 -0500
Message-ID: <A2299BB.FF7788@example.org>
From: <recipient@example.org>
To: <0123456789@sms.example.net>
Subject: From Knitting list: A new sweater
Leiba & Haardt Expires April 19, 2007 [Page 7]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
Note that:
o Fields such as "Message-ID:" and "Date:" were generated afresh for
the notification message, and do not relate to the triggering
message.
o Additional "Received:" fields will be added to the notification
message in transit; the ones shown were copied from the triggering
message.
o If this message should appear at the mail.example.org server
again, the server can use the presence of a "mail.example.org"
received line to avoid sending another notification.
Leiba & Haardt Expires April 19, 2007 [Page 8]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
4. Internationalization Considerations
[[Internationalization: What do we say here?]]
Leiba & Haardt Expires April 19, 2007 [Page 9]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
5. Security Considerations
Sending a notification is comparable with forwarding mail to the
notification recipient. Care must be taken when forwarding mail
automatically, to ensure that confidential information is not sent
into an insecure environment.
The automated sending of email messages exposes the system to mail
loops, which can cause operational problems. Implementations of this
specification MUST protect themselves against mail loops.
Additional security considerations are discussed in [Sieve] and in
[Notify].
Leiba & Haardt Expires April 19, 2007 [Page 10]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
6. IANA Considerations
[[IANA to-do: What do we need to do to actually get this set up with
IANA?]]
The following template specifies the IANA registration of the Sieve
notification mechanism specified in this document:
To: iana@iana.org
Subject: Registration of new Sieve notification mechanism
Mechanism name: mailto
Mechanism URI: draft-duerst-mailto-bis (change to RFC----)
Mechanism-specific tags: none
Standards Track/IESG-approved experimental RFC number: this RFC
Person and email address to contact for further information:
Michael Haardt <michael.haardt@freenet-ag.de>
This information should be added to the list of sieve notification
mechanisms given on
http://www.iana.org/assignments/sieve-notification.
Leiba & Haardt Expires April 19, 2007 [Page 11]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
7. References
7.1. Normative References
[Kwds] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997.
[Notify] Melnikov, A., Ed., Leiba, B., Ed., Segmuller, W., and T.
Martin, "Sieve Extension: Notifications", work in
progress, draft-ietf-sieve-notify, December 2005.
[Sieve] Guenther, P., Ed. and T. Showalter, Ed., "Sieve: An Email
Filtering Language", work in
progress, draft-ietf-sieve-3028bis, November 2005.
[mailto] Duerst, M., Masinter, L., and J. Zawinski, "The mailto URI
scheme", work in progress, draft-duerst-mailto-bis,
February 2005.
7.2. Non-Normative References
[ABNF] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 4234, October 2005.
[RFC2821] Klensin, J., Ed., "Simple Mail Transfer Protocol",
RFC 2821, April 2001.
[Variables]
Homme, K., "Sieve Extension: Variables", work in
progress, draft-ietf-sieve-variables, October 2005.
Leiba & Haardt Expires April 19, 2007 [Page 12]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
Authors' Addresses
Barry Leiba
IBM T.J. Watson Research Center
19 Skyline Drive
Hawthorne, NY 10532
US
Phone: +1 914 784 7941
Email: leiba@watson.ibm.com
Michael Haardt
freenet.de AG
Willstaetter Str. 13
Duesseldorf, NRW 40549
Germany
Phone: +49 241 53087 520
Email: michael.haardt@freenet-ag.de
Leiba & Haardt Expires April 19, 2007 [Page 13]
Internet-Draft Sieve Notification Mechanism: mailto October 2006
Full Copyright Statement
Copyright (C) The Internet Society (2006).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM 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 MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
Acknowledgment
Funding for the RFC Editor function is currently provided by the
Internet Society.
Leiba & Haardt Expires April 19, 2007 [Page 14]
