NAME
    Net::IMAP::Server - A single-threaded multiplexing IMAP server
    implementation, using Net::Server::Coro.

SYNOPSIS
      use Net::IMAP::Server;
      Net::IMAP::Server->new(
          port        => 193,
          ssl_port    => 993,
          auth_class  => "Your::Auth::Class",
          model_class => "Your::Model::Class",
          user        => "nobody",
          group       => "nobody",
      )->run;

DESCRIPTION
    This model provides a complete implementation of the "RFC 3501"
    specification, along with several IMAP4rev1 extensions. It provides
    separation of the mailbox and message store from the client interaction
    loop.

    Note that, following RFC suggestions, login is not allowed except under
    a either SSL or TLS. Thus, you are required to have a certs/ directory
    under the current working directory, containing files server-cert.pem
    and "server-key.pem". Failure to do so will cause the server to fail to
    start. Note that if the default paths suit your needs, you can specify
    different ones using the "server_cert" and "server_key" arguments to
    "new".

INTERFACE
    The primary method of using this module is to supply your own model and
    auth classes, which inherit from Net::IMAP::Server::DefaultModel and
    Net::IMAP::Server::DefaultAuth. This allows you to back your messages
    from arbitrary data sources, or provide your own authorization backend.
    For the most part, the implementation of the IMAP components should be
    opaque.

METHODS
  new PARAMHASH
    Creates a new IMAP server object. This doesn't even bind to the sockets;
    it merely initializes the object. It will "die" if it cannot find the
    appropriate certificate files. Valid arguments to "new" include:

    port
        The port to bind to. Defaults to port 1430.

    ssl_port
        The port to open an SSL listener on; by default, this is disabled,
        and any true value enables it.

    auth_class
        The name of the class which implements authentication. This must be
        a subclass of Net::IMAP::Server::DefaultAuth.

    model_class
        The name of the class which implements the model backend. This must
        be a subclass of Net::IMAP::Server::DefaultModel.

    connection_class
        On rare occasions, you may wish to subclass the connection class;
        this class must be a subclass of Net::IMAP::Server::Connection.

    poll_every
        How often the current mailbox should be polled, in seconds; defaults
        to 0, which means it will be polled after every client command.

    unauth_commands
        The number of commands before unauthenticated users are
        disconnected. The default is 10; set to zero to disable.

    unauth_idle
        How long, in seconds, to wait before disconnecting idle connections
        which have not authenticated yet. The default is 5 minutes; set to
        zero to disable (which is not advised).

    auth_idle
        How long, in seconds, to wait before disconnecting authenticated
        connections. By RFC specification, this must be longer than 30
        minutes. The default is an hour; set to zero to disable.

    server_cert
        Path to the SSL certificate that the server should use. This can be
        either a relative or absolute path.

    server_key
        Path to the SSL certificate key that the server should use. This can
        be either a relative or absolute path.

    It also accepts the following Net::Server arguments -- see its
    documentation for details on their use.

    "log_level" in Net::Server
    "log_file" in Net::Server
    "syslog_logsock" in Net::Server
    "syslog_ident" in Net::Server
    "syslog_logopt" in Net::Server
    "syslog_facility" in Net::Server
    "pid_file" in Net::Server
    "chroot" in Net::Server
    "user" in Net::Server
    "group" in Net::Server
    "reverse_lookups" in Net::Server
    "allow" in Net::Server
    "deny" in Net::Server
    "cidr_allow" in Net::Server
    "cidr_deny" in Net::Server

  run
    Starts the server; this method shouldn't be expected to return. Within
    this method, $Net::IMAP::Server::Server is set to the object that this
    was called on; thus, all IMAP objects have a way of referring to the
    server -- and though "connection", whatever parts of the IMAP internals
    they need.

    Any arguments are passed through to "run" in Net::Server.

  process_request
    Accepts a client connection; this method is needed for the Net::Server
    infrastructure.

  DESTROY
    On destruction, ensure that we close all client connections and
    listening sockets.

  connections
    Returns an arrayref of Net::IMAP::Server::Connection objects which are
    currently connected to the server.

  connection
    Returns the currently active Net::IMAP::Server::Connection object, if
    there is one. This is determined by examining the current coroutine.

  concurrent_mailbox_connections [MAILBOX]
    This can be called as either a class method or an instance method; it
    returns the set of connections which are concurrently connected to the
    given mailbox object (which defaults to the current connection's
    selected mailbox)

  concurrent_user_connections [USER]
    This can be called as either a class method or an instance method; it
    returns the set of connections whose "user" in
    Net::IMAP::Server::DefaultAuth is the same as the given USER (which
    defaults to the current connection's user)

  capability
    Returns the "CAPABILITY" string for the server. This string my be
    modified by the connection before being sent to the client (see
    "capability" in Net::IMAP::Server::Connection).

  id
    Returns a hash of properties to be conveyed to the client, should they
    ask the server's identity.

  add_command NAME => PACKAGE
    Adds the given command "NAME" to the server's list of known commands.
    "PACKAGE" should be the name of a class which inherits from
    Net::IMAP::Server::Command.

  log SEVERITY, MESSAGE
    By default, defers to "log" in Net::Server, which outputs to syslog, a
    logfile, or STDERR, depending how it was configured. Net::Server's
    default is to print to STDERR. If you have custom logging needs,
    override this method, or "write_to_log_hook" in Net::Server.

Object model
    An ASCII model of the relationship between objects is below. In it,
    single lines represent scalar values, and lines made of other characters
    denote array references or relations.

       +----------------------------------------------+
       |                                              |
       |                    Server                    |
       |                                              |
       +1-----2---------------------------------------+
        #     |      ^         ^            ^        ^
        #     |      |         |            |        |
        #     v      |         |            |        |
        #   +--------1-------+ |     +------1------+ |
        ###>|   Connection   |<------2   Command   | |
        #   +--4-----3------2+ |     +-------------+ |
      ,-#------'     |      `--------------.         |
      | #            v         |           v         |
      | #   +----------------+ |     +-------------+ |
      | #   |     Model      2------>|    Auth     | |
      | #   +--------1-------+ |     +-------------+ |
      | #            `---------------------------------.
      | #                      |                     | |
      | #                  ,---'                 ,---' |
      | #   +--------------1-+       +-----------1-+   |
      | ###>|   Connection   |<------2   Command   |   |
      |     +--4-5---3------2+       +-------------+   |
      | ,------' *   |      `--------------.           |
      | | ********   v                     v           |
      | | * +----------------+       +-------------+   |
      | | * |     Model      2------>|    Auth     |   |
      | | * +--------1-------+       +-------------+   |
      | | *          |                                 |
      | | *          |  ,------------------------------'
      | | *          |  |           ^ SERVER
     .|.|.*..........|..|................................
      | | *          |  |           v MODEL
      | | *          v  v
      | '-*---->+-------------+<------------.
      '---*---->|   Mailbox   |<----------. |
          *     +-1------2-3--+<----.     | |
          *       @   ^  $ %        |     | |
          *       @   |  $$$$>+-----1---+ | |
          *       @   |  $ %  |         | | |
          *       @   |  $ %%>| Message | | |
          *       @   |  $ %  |         | | |
          ********@***|******>+---------+ | |
          *       @   |  $ %              | |
          *       @   |  $$$$>+---------+ | |
          *       @   |    %  |         | | |
          *       @   |    %%>| Message 1-' |
          *       @   |       |         |   |
          ********@***|******>+---------+   |
          *       @   |                     |
          *       @   |       +---------+   |
          *       @   |       | Message 1---'
          ********@***|******>+---------+
                  @   |
                  @  +4----------+
                  @@>|  Mailbox  |
                     +-----------+

    The top half consists of the parts which implement the IMAP protocol
    itself; the bottom contains the models for the backing store. Note that,
    for the most part, the backing store is unaware of the framework of the
    server itself.

    Each model has references to others, as follows:

    Server
        Contains references to the set of "connections" (1). It also has a
        sense of the *current* "connection" (2), based on the active Coro
        thread.

    Connection
        Connections hold a reference to their "server" (1). If the
        connection has authenticated, they hold a reference to the "auth"
        object (2), and to their "model" (3). If a mailbox is "selected"
        (4), they hold a pointer to that, as well. Infrequently, the
        connection will need to temporarily store references to the set of
        "temporary_messages" (5) which have been expunged in other
        connections, but we have been unable to notify this connection of.

    Command
        Commands store their "server" (1) and "connection" (2).

    Model
        Models store a reference to the "root" (1) of their mailbox tree, as
        well as to the "auth" (2) which gives them access to such.

    Mailbox
        Mailboxes store a list of "children" mailboxes (1), and "messages"
        (2) contained within them, which are stored in sequence order. They
        also contain a hash of "uids" (3) for fast UID retrieval of
        messages. If they are not the root mailbox, they also store a
        reference to their "parent" mailbox (4).

    Message
        Messages store the "mailbox" (1) in which they are contained.

DEPENDENCIES
    Coro, Net::Server::Coro

BUGS AND LIMITATIONS
    No bugs have been reported.

    Please report any bugs or feature requests to
    "bug-net-imap-server@rt.cpan.org", or through the web interface at
    <http://rt.cpan.org>.

    A low-traffic mailing list exists for discussion on how to (ab)use this
    module, at
    <http://lists.bestpractical.com/cgi-bin/mailman/listinfo/net-imap-server
    >.

AUTHOR
    Alex Vandiver "<alexmv@bestpractical.com>"

LICENCE AND COPYRIGHT
    Copyright (c) 2010, Best Practical Solutions, LLC. All rights reserved.

    This module is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself. See perlartistic.

DISCLAIMER OF WARRANTY
    BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
    FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
    OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
    PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
    EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
    ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
    YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
    NECESSARY SERVICING, REPAIR, OR CORRECTION.

    IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
    WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
    REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE
    TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR
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    SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
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    DAMAGES.

