Provided by: dovecot-core_2.3.19.1+dfsg1-2ubuntu2_amd64 bug


       pigeonhole  -  Overview  of  the Pigeonhole project's Sieve support for the Dovecot secure
       IMAP and POP3 server


       The Pigeonhole project <> adds support for the Sieve language
       (RFC  5228)  and  the  ManageSieve protocol (RFC 5804) to the Dovecot Secure IMAP and POP3
       Server (dovecot(1)). In the literal sense, a pigeonhole is a a hole  or  recess  inside  a
       dovecot  for  pigeons  to  nest  in.  It is, however, also the name for one of a series of
       small, open compartments in a cabinet used for filing or  sorting  mail.  As  a  verb,  it
       describes  the act of putting an item into one of those pigeonholes. The name "Pigeonhole"
       therefore well describes an important part of the functionality that this project adds  to
       Dovecot: sorting and filing e-mail messages.

       The  Sieve  language is used to specify how e-mail needs to be processed. By writing Sieve
       scripts, users can customize how messages are delivered, e.g.  whether they are  forwarded
       or  stored  in  special folders. Unwanted messages can be discarded or rejected, and, when
       the user is not available, the Sieve interpreter can send an automated reply.  Above  all,
       the  Sieve  language is meant to be simple, extensible and system independent. And, unlike
       most other mail filtering script languages, it does not allow users to  execute  arbitrary
       programs.  This is particularly useful to prevent virtual users from having full access to
       the mail store. The intention of the language is to make it impossible  for  users  to  do
       anything more complex (and dangerous) than write simple mail filters.

       Using  the  ManageSieve  protocol,  users can upload their Sieve scripts remotely, without
       needing direct filesystem access through FTP or SCP. Additionally,  a  ManageSieve  server
       always  makes  sure  that  uploaded scripts are valid, preventing compile failures at mail

       The Pigeonhole project provides the following items:

       •   The LDA Sieve plugin for Dovecot's Local Delivery Agent  (LDA)  (dovecot-lda(1))  that
           facilitates the actual Sieve filtering upon delivery.

       •   The  ManageSieve  service that implements the ManageSieve protocol through which users
           can remotely manage Sieve scripts on the server.

       •   A plugin for Dovecot's doveadm(1) command line tool that adds  new  the  new  doveadm-
           sieve(1) commands for management of Sieve filtering.

       The functionality and configuration of the LDA Sieve plugin and the ManageSieve service is
       described in detail in the README and INSTALL files contained in  the  Pigeonhole  package
       and in the Dovecot Wiki <>.

       The following command line tools are available outside of doveadm:

              Compiles Sieve scripts into a binary representation for later execution.

              The  universal  Sieve  test  tool  for  testing  the  effect of a Sieve script on a
              particular message.

              Filters all messages in a particular source mailbox through a Sieve script.

              Dumps the content of a Sieve binary file for (development) debugging purposes.


       Report   bugs,   including   doveconf   -n   output,   to   the   Dovecot   Mailing   List
       <>.     Information    about    reporting   bugs   is   available   at:


       Pigeonhole <> and  its  manual  pages  were  written  by  the
       Pigeonhole   authors  <>,  mainly  Stephan  Bosch
       <stephan at>, and are licensed under the terms of the LGPLv2.1 license, which
       is the same license as Dovecot, see <> for details.


       dovecot(1),  dovecot-lda(1),  doveadm(1),  doveadm-sieve(1), sieve-dump(1), sieve-test(1),
       sieve-filter(1), sievec(1)

       Additional resources:

       Dovecot website

       Dovecot v2.x Wiki

       Pigeonhole website