Sieve Email Filtering: MIME Part Tests, Iteration, Extraction, Replacement, and Enclosure
RFC 5703

Network Working Group                                          T. Hansen
Request for Comments: 5703                             AT&T Laboratories
Category: Standards Track                                       C. Daboo
                                                              Apple Inc.
                                                            October 2009

     Sieve Email Filtering: MIME Part Tests, Iteration, Extraction,
                       Replacement, and Enclosure

Abstract

   This document defines extensions to the Sieve email filtering
   language to permit analysis and manipulation of the MIME body parts
   of an email message.

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.

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Hansen & Daboo              Standards Track                     [Page 1]
RFC 5703                 Sieve MIME Operations              October 2009

   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.

Table of Contents

   1. Introduction ....................................................2
   2. Conventions Used in This Document ...............................3
   3. Sieve Loops: Actions "foreverypart" and "break" .................3
   4. Changes to Sieve Tests ..........................................4
      4.1. Test "header" ..............................................4
      4.2. Test "address" .............................................7
      4.3. Test "exists" ..............................................8
   5. Action "replace" ................................................8
   6. Action "enclose" ...............................................10
   7. Action "extracttext" ...........................................11
   8. Sieve Capability Strings .......................................11
   9. Examples .......................................................12
      9.1. Example 1 .................................................12
      9.2. Example 2 .................................................12
      9.3. Example 3 .................................................13
   10. Acknowledgements ..............................................13
   11. Security Considerations .......................................14
   12. IANA Considerations ...........................................14
      12.1. foreverypart capability ..................................15
      12.2. mime capability ..........................................15
      12.3. replace capability .......................................15
      12.4. enclose capability .......................................16
      12.5. extracttext capability ...................................16
   13. References ....................................................16
      13.1. Normative References .....................................16
      13.2. Informative References ...................................17

1.  Introduction

   MIME messages ([RFC2045]) are often complex objects, consisting of
   many parts and sub-parts.  This Sieve ([RFC5228]) extension defines
   mechanisms for performing tests on MIME body parts, looping through