Network Working Group                                       T. Showalter
Internet Draft: Sieve Vacation                           Carnegie Mellon
Document: draft-showalter-sieve-vacation-00.txt             January 1998
Expire in six months (31 Jun 1998)

                      Sieve -- Vacation Extension

Status of this memo

   This document is an Internet-Draft.  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.''

   To learn the current status of any Internet-Draft, please check the
   ``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow
   Directories on (Africa), (Europe), (Pacific Rim), (US East Coast), or (US West Coast).

   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 1998.  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.  The extension is offered in the hopes of making frequently
   used commands availible (and discouraging users from implementing it

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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 compared with the Sieve mail filtering
   language, an Internet-Draft 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 <reason-string>

   The "vacation" action implements a vacation autoresponder similar to
   the vacation command  availible under many versions of Unix.  Its
   purpose is to provide correspondants with notification that the user
   is away for an extended period of time and that they should not
   expect quick responses.

   Vacation is similar to reply as defined in [SIEVE].  Like reply in
   that document and Unix vacation, the reply goes to the address
   specified by the return-path header (the envelope "MAIL FROM"
   address), not to the addresses in the From header.

   There are a few differences:

   "Vacation" keeps track of all of the addresses that it has responded
   to in the past seven (7) days and MUST NOT respond to them a second

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   time within this period.  The "vacation" action may send out
   notifications less frequently, but should not send them out more

   Vacation is used like this:

             if header ("to", "cc") contains ("") {
               "I'm away until Octber 19.
             If it's an emergency, call 911, I guess." ;

   By mingling vacation with other rules, users can do something more

             if header "from" contains "" {
                forward "";
             } else {
                if header ("to", "cc") contains ("") {
                  vacation "Sorry, I'm away, I'll read your message when
                I get around to it.";

   However, it is important that users check for their email address in
   the To and CC lines of the input message so that the script only
   responds to mail sent to them.

4. Interaction with Other Sieve Actions

   Sieve actions sometimes prohibit each other in order to make
   filtering scripts less likely to cause serious problems.  Vacation
   has exactly the same semantics as reply, as it is strictly less
   likely to cause problems -- vacation sometimes sends out a message,
   whereas reply always does.

5. Security Considerations

   It is important that implementations correctly implement the seven-
   day limit on messages and reply to the envelope from address, not the
   From line address.

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6. Formal Grammar

   The grammar used in this section is the same as the ABNF described in

   action =/ vacation         ;; "vacation" is now a legal action

   vacation = vacation WSP string

7. Author's Address

   Tim Showalter
   Carnegie Mellon University
   5000 Forbes Avenue
   Pittsburgh, PA 15213


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Appendix A.  References

   [ABNF] Crocker, D.,  "Augmented BNF for Syntax Specifications: ABNF",
   Internet Mail Consortium, RFC 2234, November, 1997.

   [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", Carenegie
   Mellon, Work in Progress.

Appendix B. Full Copyright Statement

   Copyright (C) The Internet Society 1997. 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 will expire before June 31, 1998.

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