Mail::Transport::IMAP4(3pm)

NAME
Mail::Transport::IMAP4 - proxy to Mail::IMAPClient

INHERITANCE
 Mail::Transport::IMAP4
   is a Mail::Transport::Receive
   is a Mail::Transport
   is a Mail::Reporter

SYNOPSIS
  my $imap = Mail::Transport::IMAP4->new(...);
  my $message = $imap->receive($id);
  $imap->send($message);

  my Mail::Box::Manager $mgr = Mail::Box::Manager->new;
  $mgr->open(
      # Generic folder options
      folder => 'imaps://...',
      access => 'rw',
      extract => 'ALWAYS',

      # Mail::IMAPClient options start with [A-Z]
      IgnoreSizeErrors => 1,
      Ssl => 1,
  );

DESCRIPTION
The IMAP4 protocol is quite complicated: it is feature rich and allows various asynchronous actions. The main document describing IMAP is rfc3501 (which obsoleted the original specification of protocol 4r1 in rfc2060 in March 2003).

This package, as part of MailBox, does not implement the actual protocol itself but uses Mail::IMAPClient to do the work. The task for this package is to hide as many differences between that module's interface and the common MailBox folder types. Multiple Mail::Box::IMAP4 folders can share one Mail::Transport::IMAP4 connection.

The Mail::IMAPClient module is the best IMAP4 implementation for Perl5, but is not maintained. There are many known problems with the module, and solving those is outside the scope of MailBox. See <https://rt.cpan.org/Public/Dist/Display.html?Name=Mail-IMAPClient> for all the reported bugs.

Extends "DESCRIPTION" in Mail::Transport::Receive.

METHODS
Extends "METHODS" in Mail::Transport::Receive.

  Constructors
Extends "Constructors" in Mail::Transport::Receive.

$class->new(%options)
    Create the IMAP connection to the server. IMAP servers can handle multiple folders for a single user, which means that connections may get shared. This is sharing is hidden for the user.

    When an "imap_client" is specified, then the options "hostname", "port", "username", and "password" are extracted from it.

    All %options which start with a capital are passed as initiation to Mail::IMAPClient. See that manual about the huge pile of parameters. When talking to Microsoft Exchange, you probabaly need the "IgnoreSizeErros". Probably, you need "Ssl" or "StartTLS" as well. As feature, you may also pass a HASH to Ssl, where "Mail::IMAPClient" only accepts an ARRAY.

    For backwards compatibility, "ssl" is an alternative for "Ssl", and "starttls" for "StartTLS". Improves base, see "Constructors" in Mail::Reporter

     -Option      --Defined in     --Default
      authenticate                   'AUTO'
      domain                         <server_name>
      executable    Mail::Transport  undef
      hostname      Mail::Transport  'localhost'
      imap_client                    Mail::IMAPClient
      interval      Mail::Transport  30
      password      Mail::Transport  undef
      port          Mail::Transport  143
      proxy         Mail::Transport  undef
      retry         Mail::Transport  <unlimited>
      timeout       Mail::Transport  120
      username      Mail::Transport  undef
      via           Mail::Transport  'imap'

    authenticate => TYPE|ARRAY
        Authenthication method to login(), which will be passed to Mail::IMAPClient subroutine authenticate. See the latter method for the available types. You may provide an ARRAY of types.

    domain => WINDOWS_DOMAIN
        Used for NTLM authentication.

    executable => $file
    hostname => $host|\@hosts
    imap_client => OBJECT|CLASS
        When an OBJECT is supplied, that client will be used for the implementation of the IMAP4 protocol. Information about server and such are extracted from the OBJECT to have the accessors to produce correct results. The OBJECT shall be a Mail::IMAPClient.

        When a CLASS is given, an object of that type is created for you. The created object can be retrieved via imapClient(), and than configured as defined by Mail::IMAPClient.

    interval => $span
    password => $password
    port => $port
    proxy => $path
    retry => $count|undef
    timeout => $span
    username => $username
    via => CLASS|$name

  Attributes
Extends "Attributes" in Mail::Transport::Receive.

$obj->authentication( ['AUTO'|$type|$types] )
    Returns a LIST of ARRAYS, each describing one possible way to contact the server. Each pair contains a mechanism name and a challenge callback (which may be "undef").

    The settings are used by login() to get server access. The initial value origins from new(authenticate), but may be changed later.

    Available basic $types are "CRAM-MD5", "NTLM", and "PLAIN". With "AUTO", all available types will be tried. When the Authen::NTLM is not installed, the "NTLM" option will silently be skipped. Be warned that, because of "PLAIN", erroneous username/password combinations will be passed readible as last attempt!

    The "NTLM" authentication requires Authen::NTLM to be installed. Other methods may be added later. Besides, you may also specify a CODE reference which implements some authentication.

    An ARRAY as $type can be used to specify both mechanism as callback. When no array is used, callback of the pair is set to "undef". See "authenticate" in Mail::IMAPClient for the gory details.

    » example:

      $transporter->authentication('CRAM-MD5', [MY_AUTH => \&c], 'PLAIN');

      foreach my $pair ($transporter->authentication)
      {   my ($mechanism, $challenge) = @$pair;
          ...
      }

$obj->domain( [$domain] )
    Used in NTLM authentication to define the Windows domain which is accessed. Initially set by new(domain) and defaults to the server's name.

$obj->usesSSL()
    Returns a boolean.

  Receiving mail
Extends "Receiving mail" in Mail::Transport::Receive.

$obj->receive( [$unique_message_id] )
    Inherited, see "Receiving mail" in Mail::Transport::Receive

  Server connection
Extends "Server connection" in Mail::Transport::Receive.

$obj->findBinary( $name, [@directories] )
    Inherited, see "Server connection" in Mail::Transport

$obj->remoteHost()
    Inherited, see "Server connection" in Mail::Transport

$obj->retry()
    Inherited, see "Server connection" in Mail::Transport

  Exchanging Information

  Protocol [internals]
The follow methods handle protocol internals, and should not be used by a normal user of this class.

$obj->appendMessage( $message, $foldername, [$date] )
    Write the message to the server. The optional DATA can be a RFC-822 date or a timestamp.

$obj->createFolder($name)
    Add a folder.

$obj->createImapClient($class, %options)
    Create an object of $class, which extends Mail::IMAPClient.

$obj->currentFolder( [$foldername] )
    Be sure that the specific FOLDER is the current one selected. If the folder is already selected, no IMAP traffic will be produced.

    The boolean return value indicates whether the folder is selectable. It will return "undef" if it does not exist.

$obj->deleteFolder($name)
    Remove one folder.

$obj->destroyDeleted($folder)
    Command the server to delete for real all messages which are flagged to be deleted.

$obj->fetch(\@messages, $info)
    Get some $info about the @messages from the server. The specified messages shall extend Mail::Box::Net::Message, Returned is a list of hashes, each info about one result. The contents of the hash differs per $info, but at least a "message" field will be present, to relate to the message in question.

    The right folder should be selected before this method is called. When the connection was lost, "undef" is returned. Without any messages, and empty array is returned. The retrieval is done by Mail::IMAPClient method fetch(), which is then parsed.

$any->flagsToLabels($what, @flags)
    In SCALAR context, a hash with labels is returned. In LIST context, pairs are returned.

    The $what parameter can be 'SET', 'CLEAR', or 'REPLACE'. With the latter, all standard imap flags which do not appear in the list will be ignored: their value may either by set or cleared. See getFlags()

    Unknown flags in @flags are stripped from their backslash and lower-cased. For instance, '\SomeWeirdFlag' will become `someweirdflag => 1'. It will be set to '1' for "SET", and '0' in case of "CLEAR".

    » example: translating IMAP4 flags into MailBox flags

      my @flags  = ('\Seen', '\Flagged');
      my $labels = Mail::Transport::IMAP4->flags2labels(SET => @flags);

$obj->folders( [$foldername] )
    Returns a list of folder names which are sub-folders of the specified $foldername. Without $foldername, the top-level foldernames are returned.

$obj->getFields( $uid, $name, [$name, ...] )
    Get the records with the specified NAMES from the header. The header fields are returned as list of Mail::Message::Field::Fast objects. When the name is "ALL", the whole header is returned.

$obj->getFlags($folder, $id)
    Returns the values of all flags which are related to the message with the specified $id. These flags are translated into the names which are standard for the MailBox suite.

    A HASH is returned. Names which do not appear will also provide a value in the returned: the negative for the value is it was present.

$obj->getMessageAsString($message|$uid)
    Returns the whole text of the specified message: the head and the body.

$obj->ids()
    Returns a list of UIDs which are defined by the IMAP server.

$obj->imapClient()
    Returns the object which implements the IMAP4 protocol, an instance of a Mail::IMAPClient, which is logged-in and ready to use.

    If the contact to the server was still present or could be established, an Mail::IMAPClient object is returned. Else, "undef" is returned and no further actions should be tried on the object.

$any->labelsToFlags(HASH|PAIRS)
    Convert MailBox labels into IMAP flags. Returned is a string. Unsupported labels are ignored.

$obj->listFlags()
    Returns all predefined flags as list.

$obj->login()
    Establish a new connection to the IMAP4 server, using username and password.

$obj->setFlags($id, $label, $value, [$label, $value], ...)
    Change the flags on the message which are represented by the label. The value which can be related to the label will be lost, because IMAP only defines a boolean value, where MailBox labels can contain strings.

    Returned is a list of ($label => $value) pairs which could not be send to the IMAP server. These values may be cached in a different way.

  Error handling
Extends "Error handling" in Mail::Transport::Receive.

$obj->AUTOLOAD()
    Inherited, see "Error handling" in Mail::Reporter

$obj->notImplemented()
    Inherited, see "Error handling" in Mail::Reporter

  Cleanup
Extends "Cleanup" in Mail::Transport::Receive.

$obj->DESTROY()
    The connection is cleanly terminated when the program is terminated. Improves base, see "Cleanup" in Mail::Reporter

DIAGNOSTICS

Notice: IMAP4 authenication $type to $service successful
    Cast by login()

Error: IMAP4 cannot connect to $service: $@
    Cast by login()

Error: IMAP4 requires a username and password
    Cast by login()

Error: IMAP4 username $user requires a password
    Cast by login()

Error: cannot create imap client: {error}
    Cast by createImapClient()

Error: class $package does not implement method $method.
    Fatal error: the specific $package (or one of its superclasses) does not implement this method where it should. This message means that some other related classes do implement this method however the class at hand does not. Probably you should investigate this and probably inform the author of the package. Cast by notImplemented()

Error: couldn't contact to IMAP4 $service
    Cast by login()

Notice: couldn't select folder $name but it does exist.
    Cast by currentFolder()

Warning: failed attempt to login $user, retrying $retries times.
    Cast by login()

Notice: folder $name does not exist!
    Cast by currentFolder()

Notice: selected IMAP4 folder $name.
    Cast by currentFolder()

SEE ALSO
This module is part of Mail-Box-IMAP4 version 4.01, built on December 13, 2025. Website: http://perl.overmeer.net/CPAN/

LICENSE
For contributors see file ChangeLog.

This software is copyright (c) 2001-2025 by Mark Overmeer.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.