RFC 3431 (rfc3431) - Page 1 of 8

Sieve Extension: Relational Tests

Network Working Group                                       W. Segmuller
Request for Comment: 3431                IBM T.J. Watson Research Center
Category: Standards Track                                  December 2002


                   Sieve Extension: Relational Tests

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   This document describes the RELATIONAL extension to the Sieve mail
   filtering language defined in RFC 3028.  This extension extends
   existing conditional tests in Sieve to allow relational operators.
   In addition to testing their content, it also allows for testing of
   the number of entities in header and envelope fields.

1 Introduction

   Sieve [SIEVE] is a language for filtering e-mail messages at the time
   of final delivery.  It is designed to be implementable on either a
   mail client or mail server.  It is meant to be extensible, simple,
   and independent of access protocol, mail architecture, and operating
   system.  It is suitable for running on a mail server where users may
   not be allowed to execute arbitrary programs, such as on black box
   Internet Messages Access Protocol (IMAP) servers, as it has no
   variables, loops, nor the ability to shell out to external programs.

   The RELATIONAL extension provides relational operators on the
   address, envelope, and header tests.  This extension also provides a
   way of counting the entities in a message header or address field.

   With this extension, the sieve script may now determine if a field is
   greater than or less than a value instead of just equivalent.  One
   use is for the x-priority field: move messages with a priority
   greater than 3 to the "work on later" folder.  Mail could also be
   sorted by the from address.  Those userids that start with 'a'-'m' go
   to one folder, and the rest go to another folder.



Segmuller                   Standards Track