Network Working Group                                       T. Showalter
Internet Draft: Sieve: Vacation Extension                Carnegie Mellon
Document: draft-showalter-sieve-vacation-01.txt        February 24, 1999
Expire in six months

                       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-

   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

   The list of Internet-Draft Shadow Directories can be accessed at

   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 (C) The Internet Society 1999.  All Rights Reserved.


   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] <reason: 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

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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.

             require "vacation";
             vacation :days 23 :addresses ["", ""]
                "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

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             require "vacation";
             if header :contains "from" "" {
                redirect "";
             } 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


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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

   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

This document will expire before 31 July 1999.

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