Internet Draft
Network Working Group T. Showalter
Internet Draft: Sieve: Vacation Extension Carnegie Mellon
Document: draft-showalter-sieve-vacation-01.txt February 24, 1999
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Sieve: Vacation Extension
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 working documents as Internet-
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
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The list of current Internet-Drafts can be accessed at
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The protocol discussed in this document is experimental and subject
to change. Persons planning on either implementing or using this
protocol are STRONGLY URGED to get in touch with the author before
embarking on such a project.
Copyright
Copyright (C) The Internet Society 1999. All Rights Reserved.
Abstract
This document describes an extension to the Sieve mail filtering
language for an autoresponder similar to that of the Unix "vacation"
command for replying to messages with certain safety features to
prevent problems.
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0. Meta-information on this draft
This information is intended to facilitate discussion. It will be
removed when this document leaves the Internet-Draft stage.
0.1. Discussion
This draft is intended to be an extension to the Sieve mail filtering
language, avaliable from the Internet-Drafts repository as
(where 07 is the version number, which is actually currently 07).
This draft and the Sieve language itself are being discussed on the
MTA Filters mailing list at . Subscription
requests can be sent to (send an
email message with the word "subscribe" in the body). More
information on the mailing list along with a WWW archive of back
messages is available at .
1. Introduction
This is an extension to the Sieve language defined by [SIEVE] for
notification that messages will not be immediately answered.
Conventions for notations are as in [SIEVE] section 1.1, including
use of [KEYWORDS].
2. Capability Identifier
Sieve implementations that implement vacation have an identifier of
"vacation" for use with the capability mechanism.
3. Vacation Action
Syntax: vacation [":days" number] [":addresses" string-list]
[":subject" string]
The "vacation" action implements a vacation autoresponder similar to
the vacation command available under many versions of Unix. Its
purpose is to provide correspondents with notification that the user
is away for an extended period of time and that they should not
expect quick responses.
"Vacation" is used to respond to a message with another message.
Vacation's messages are always addressed to the Return-Path address
(that is, the envelope from address) of the message being responded
to.
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The ":days" argument is used to specify the period in which addresses
are kept and are not responded to, and is always specified in days.
The minimum value used for this parameter is 1. Sites MAY define a
different minimum value. Sites MAY also define a maximum days value,
which MUST be greater than 7, and SHOULD be greater than 30.
If ":days" is omitted, the default value is 7, or the minimum value
(as defined above), whichever is greater.
If the parameter given to ":days" is greater than the minimum value,
then the minimum value is used instead.
If ":days" exceeds the site-defined maximum, the site-defined maximum
is used instead.
"Vacation" keeps track of all of the addresses that it has responded
to in some period (as specified by the :days optional argument). If
vacation has not previously responded to this address within that
time period, it sends the "reason" argument to the Return-Path
address of the message that is being responded to.
"Vacation" never responds to a message unless the user's email
address is in the "To" or "Cc" line of the original message.
Implementations are assumed to be able to know this information, but
users may have additional addresses beyond the control of the local
mail system.
Users can supply additional mail addresses that are theirs with the
":addresses" argument, which takes a string-list listing additional
addresses that a user might have.
Users can specify the subject of the reply with the ":subject"
parameter. If the :subject parameter is not supplied, then the
subject is generated as follows: The subject is set to the characters
"Re: " followed by the original subject with all leading occurrence
of the characters "Re: " stripped off.
Replies must have the In-Reply-To field set to the Message-ID of the
original message.
Example:
require "vacation";
vacation :days 23 :addresses ["tjs@znic.edu", "ts4z@landru.edu"]
"I'm away until October 19. If it's an emergency, call
911, I guess." ;
By mingling vacation with other rules, users can do something more
selective.
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Example:
require "vacation";
if header :contains "from" "boss@frobnitzm.edu" {
redirect "pleeb@xanadu.wv.us";
} else {
vacation "Sorry, I'm away, I'll read your message
when I get around to it.";
}
4. Interaction with Other Sieve Actions
Vacation does not affect the implicit keep.
Vacation may not be used with reject.
5. Security Considerations
It is critical that implementations correctly implement the
limitations described above: Replies MUST NOT be sent out in response
to messages not sent directly to the user, and replies MUST NOT be
sent out more often than the :days argument states.
6. Author's Address
Tim Showalter
Carnegie Mellon University
5000 Forbes Avenue
Pittsburgh, PA 15213
E-Mail: tjs+@andrew.cmu.edu
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Appendix A. References
[KEYWORDS] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, Harvard University, March 1997.
[SIEVE] Showalter, T., "Sieve: A Mail Filtering Language", Carnegie
Mellon, Work in Progress.
Appendix B. Full Copyright Statement
Copyright (C) The Internet Society 1999. 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
and distributed, in whole or in part, without restriction of any
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
copyrights defined in the Internet Standards process must be
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
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
This document will expire before 31 July 1999.
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