Mail::Box::IMAP4(3pm)

NAME
Mail::Box::IMAP4 - handle IMAP4 folders as client

INHERITANCE
 Mail::Box::IMAP4
   is a Mail::Box::Net
   is a Mail::Box
   is a Mail::Reporter

 Mail::Box::IMAP4 is extended by
   Mail::Box::IMAP4s

SYNOPSIS
  my $url = 'imap4://user:passwd@host:port/INBOX';
  my $url = 'imap://user:passwd@host:port/INBOX';

  use Mail::Box::IMAP4;
  my $folder = Mail::Box::IMAP4->new(folder => $url, ...);

  use Mail::Box::Manager;
  my $mgr    = Mail::Box::Manager->new;
  my $folder = $msg->open($url, retry => 3, interval => 5);

DESCRIPTION
Maintain a folder which has its messages stored on a remote server. The communication between the client application and the server is implemented using the IMAP4 protocol. See also Mail::Server::IMAP4.

Be aware: This module versions 4.0 and up is not fully compatible with older releases: mainly the exception handling has changed. When you need to upgrade, please read https://github.com/markov2/perl5-Mail-Box/wiki/ Version 3 is still maintained and may see new releases as well.

This class uses Mail::Transport::IMAP4 to hide the transport of information, and focusses solely on the correct handling of messages within a IMAP4 folder. More than one IMAP4 folder can be handled by one single IMAP4 connection.

Extends "DESCRIPTION" in Mail::Box::Net.

OVERLOADED
Extends "OVERLOADED" in Mail::Box::Net.

overload: "" stringification
    Inherited, see "OVERLOADED" in Mail::Box

overload: @{} use as ARRAY
    Inherited, see "OVERLOADED" in Mail::Box

overload: cmp string comparison
    Inherited, see "OVERLOADED" in Mail::Box

METHODS
Extends "METHODS" in Mail::Box::Net.

  Constructors
Extends "Constructors" in Mail::Box::Net.

$class->new(%options)
    The "new" can have many %options. Not only the ones listed here below, but also all the %options for Mail::Transport::IMAP4::new() can be passed.

    The default depends on the value of new(cache_head).

    Without folder name, no folder is selected. Only few methods are available now, for instance listSubFolders() to get the top-level folder names. Usually, the folder named "INBOX" will be present. Improves base, see "Constructors" in Mail::Box

     -Option           --Defined in     --Default
      access             Mail::Box        'r'
      body_delayed_type  Mail::Box        Mail::Message::Body::Delayed
      body_type          Mail::Box        Mail::Message::Body::Lines
      cache_body                          NO
      cache_head                          NO or DELAY
      cache_labels                        NO or DELAY
      coerce_options     Mail::Box        +[]
      create             Mail::Box        false
      extract            Mail::Box        10240
      field_type         Mail::Box        undef
      fix_headers        Mail::Box        false
      folder             Mail::Box        /
      folderdir          Mail::Box        <network location>
      head_delayed_type  Mail::Box        Mail::Message::Head::Delayed
      head_type          Mail::Box        Mail::Box::IMAP4::Head or Mail::Message::Head::Complete
      join_connection                     true
      keep_dups          Mail::Box        false
      lock_file          Mail::Box        undef
      lock_timeout       Mail::Box        1 hour
      lock_type          Mail::Box        'NONE'
      lock_wait          Mail::Box        10 seconds
      locker             Mail::Box        undef
      manager            Mail::Box        undef
      message_type       Mail::Box        Mail::Box::IMAP4::Message
      multipart_type     Mail::Box        Mail::Message::Body::Multipart
      password           Mail::Box::Net   undef
      remove_when_empty  Mail::Box        <false>
      save_on_exit       Mail::Box        true
      server_name        Mail::Box::Net   undef
      server_port        Mail::Box::Net   143
      transporter                         Mail::Transport::IMAP4
      trusted            Mail::Box        <false>
      username           Mail::Box::Net   undef

    access => $mode
    body_delayed_type => CLASS
    body_type => CLASS|CODE
    cache_body => 'NO'|'YES'|'DELAY'
        Body objects are immutable, but may still cached or not. In common case, the body of a message is requested via Mail::Message::body() or Mail::Message::decoded(). This returns a handle to a body object. You may decide whether that body object can be reused or not. "NO" means: retrieve the data each time again, "YES" will cache the body data, "DELAY" will send the whole message when the folder is closed.

          [local cache]  [write]
         NO         no           no
         YES        yes          no
         DELAY      yes          yes

    cache_head => 'NO'|'PARTIAL'|'DELAY'
        For a read-only folder, "DELAY" is the default, otherwise "NO" is chosen. The four configuration parameter have subtile consequences. To start with a table:

          [local cache]  [write]  [default head_type]
         NO         no           no     Mail::Box::IMAP4::Head
         PARTIAL    yes          no     Mail::Box::IMAP4::Head
         DELAY      yes          yes    Mail::Message::Head::Complete

        The default "head_type" is Mail::Box::IMAP4::Head, the default "cached_head_type" is Mail::Message::Head::Complete.

        Having a local cache means that a lookup for a field is first done in a local data-structure (which extends Mail::Message::Head::Partial), and only on the remote server if it was not found. This is dangerous, because your locally cached data can be out-of-sync with the server. However, it may give you a nice performance benefit.

        "DELAY" will always collect the whole header for you. This is required when you want to look for Resent Groups (See Mail::Message::Head::ResentGroup) or other field order dependent header access. A Mail::Message::Head::Delayed will be created first.

    cache_labels => 'NO'|'WRITE'|'DELAY'
        When labels from a message are received, these values can be kept. However, this imposes dangers where the server's internal label storage may get out of sync with your data.

        With "NO", no caching will take place (but the performance will be worse). With "WRITE", all label access will be cached, but written to the server as well. Both "NO" and "WRITE" will update the labels on the served, even when the folder was opened read-only. "DELAY" will not write the changed information to the server, but delay that till the moment that the folder is closed. It only works when the folder is opened read/write or write is enforced.

        The default is "DELAY" for folders which where opened read-only. This means that you still can force an update with close(write). For folders which are opened read-write, the default is the safeset setting, which is "NO".

    coerce_options => ARRAY
    create => BOOLEAN
    extract => INTEGER|CODE|METHOD|'LAZY'|'ALWAYS'
    field_type => CLASS
    fix_headers => BOOLEAN
    folder => $name
    folderdir => $directory
    head_delayed_type => CLASS
    head_type => CLASS
    join_connection => BOOLEAN
        Within this Mail::Box::IMAP4 class is registered which transporters are already in use, i.e. which connections to the IMAP server are already in established. When this option is set, multiple folder openings on the same server will try to reuse one connection.

    keep_dups => BOOLEAN
    lock_file => $file
    lock_timeout => $seconds
    lock_type => CLASS|STRING|ARRAY
    lock_wait => $seconds
    locker => OBJECT
    manager => $manager
    message_type => CLASS
    multipart_type => CLASS
    password => $password
    remove_when_empty => BOOLEAN
    save_on_exit => BOOLEAN
    server_name => $host
    server_port => $number
    transporter => $object|$class
        The name of the $class which will interface with the connection. When you implement your own extension to Mail::Transport::IMAP4, you can either specify a fully instantiated transporter $object, or the name of your own $class. When an $object is given, most other options will be ignored.

    trusted => BOOLEAN
    username => $username

    » example:

      my $imap   = Mail::Box::IMAP4->new(username => 'myname',
         password => 'mypassword', server_name => 'imap.xs4all.nl');

      my $url    = 'imap4://user:password@imap.xs4all.nl';
      my $imap   = $mgr->open($url);

      my $client = Mail::IMAPClient->new(...);
      my $imap   = Mail::Box::IMAP4->new(imap_client => $client);

  Attributes
Extends "Attributes" in Mail::Box::Net.

$obj->fixHeaders()
    Inherited, see "Attributes" in Mail::Box

$obj->folderdir( [$directory] )
    Inherited, see "Attributes" in Mail::Box

$obj->isTrusted()
    Inherited, see "Attributes" in Mail::Box

$obj->name()
    Inherited, see "Attributes" in Mail::Box

$obj->removeEmpty()
    Inherited, see "Attributes" in Mail::Box

$obj->type()
    Inherited, see "Attributes" in Mail::Box

  The folder
Extends "The folder" in Mail::Box::Net.

$obj->addMessage($message, %options)
    Inherited, see "The folder" in Mail::Box

$obj->addMessages(@messages)
    Inherited, see "The folder" in Mail::Box

$class->appendMessages(%options)
    Inherited, see "The folder" in Mail::Box

$obj->close(%options)
    Close the folder. In the case of IMAP, more than one folder can use the same connection, therefore, closing a folder does not always close the connection to the server. Only when no folder is using the connection anymore, a logout will be invoked by Mail::Transport::IMAP4::DESTROY() Improves base, see "The folder" in Mail::Box

     -Option      --Defined in     --Default
      force         Mail::Box        false
      save_deleted  Mail::Box        false
      write         Mail::Box        'MODIFIED'

    force => BOOLEAN
    save_deleted => BOOLEAN
    write => 'ALWAYS'|'NEVER'|'MODIFIED'
$obj->copyTo($folder, %options)
    Inherited, see "The folder" in Mail::Box

$obj->delete(%options)
    Inherited, see "The folder" in Mail::Box

$obj->organization()
    Inherited, see "The folder" in Mail::Box

$obj->size()
    Inherited, see "The folder" in Mail::Box

$obj->update(%options)
    Inherited, see "The folder" in Mail::Box

$obj->url()
    Inherited, see "The folder" in Mail::Box

  Folder flags
Extends "Folder flags" in Mail::Box::Net.

$obj->access()
    Inherited, see "Folder flags" in Mail::Box

$obj->isModified()
    Inherited, see "Folder flags" in Mail::Box

$obj->modified( [BOOLEAN] )
    Inherited, see "Folder flags" in Mail::Box

$obj->writable()
    Inherited, see "Folder flags" in Mail::Box

  The messages
Extends "The messages" in Mail::Box::Net.

$obj->current( [$number|$message|$message_id] )
    Inherited, see "The messages" in Mail::Box

$obj->find($message_id)
    Inherited, see "The messages" in Mail::Box

$obj->findFirstLabeled( $label, [BOOLEAN, [\@msgs]] )
    Inherited, see "The messages" in Mail::Box

$obj->message( $index, [$message] )
    Inherited, see "The messages" in Mail::Box

$obj->messageId( $message_id, [$message] )
    Inherited, see "The messages" in Mail::Box

$obj->messageIds()
    Inherited, see "The messages" in Mail::Box

$obj->messages( <'ALL'|$range|'ACTIVE'|'DELETED'|$label| !$label|$filter> )
    Inherited, see "The messages" in Mail::Box

$obj->nrMessages(%options)
    Inherited, see "The messages" in Mail::Box

$obj->scanForMessages($message, $message_ids, $timespan, $window)
    Inherited, see "The messages" in Mail::Box

  Sub-folders
Extends "Sub-folders" in Mail::Box::Net.

$any->listSubFolders(%options)
    Inherited, see "Sub-folders" in Mail::Box

$any->nameOfSubFolder( $subname, [$parentname] )
    Inherited, see "Sub-folders" in Mail::Box

$obj->openRelatedFolder(%options)
    Inherited, see "Sub-folders" in Mail::Box

$obj->openSubFolder($subname, %options)
    Inherited, see "Sub-folders" in Mail::Box

$any->topFolderWithMessages()
    Inherited, see "Sub-folders" in Mail::Box

  Internals
Extends "Internals" in Mail::Box::Net.

$obj->body( [$body] )

$obj->coerce($message, %options)
    Inherited, see "Internals" in Mail::Box

$any->create($folder, %options)
    Inherited, see "METHODS" in Mail::Box::Net

$obj->createTransporter($class, %options)
    Create a transporter object (an instance of Mail::Transport::IMAP4), where $class defines the exact object type. As %options, everything which is acceptable to a transporter initiation can be used (see Mail::Transport::IMAP4::new().

     -Option         --Default
      join_connection  true

    join_connection => BOOLEAN
        See new(join_connection). When "false", the connection will never be shared with other IMAP mail boxes.

$obj->determineBodyType($message, $head)
    Inherited, see "Internals" in Mail::Box

$obj->fetch( <$messages|$selection>, $info )
    Low-level data retreival about one or more messages via IMAP4 from the remote server. Some of this data may differ from the information which is stored in the message objects which are created by MailBox, so you should avoid the use of this method for your own purposes. The IMAP implementation provides some wrappers around this, providing the correct behavior.

    An ARRAY of $messages may be specified or some message $selection, acceptable to Mail::Box::messages(). Examples of the latter are 'ALL', 'DELETED', or "spam" (messages labelled to contain spam).

    The $info contains one or more attributes as defined by the IMAP protocol. You have to read the full specs of the related RFCs to see these.

$class->foundIn( [$foldername], %options )
    Inherited, see "Internals" in Mail::Box

$obj->getHead($message)
    Read the header for the specified message from the remote server. "undef" is returned in case the message disappeared.

$obj->getHeadAndBody($message)
    Read all data for the specified message from the remote server. Return head and body of the mesasge as list, or an empty list if the $message disappeared from the server.

$obj->lineSeparator( [<STRING|'CR'|'LF'|'CRLF'>] )
    Inherited, see "Internals" in Mail::Box

$obj->locker()
    Inherited, see "Internals" in Mail::Box

$obj->read(%options)
    Inherited, see "Internals" in Mail::Box

$obj->readMessages(%options)
    Inherited, see "Internals" in Mail::Box

$obj->storeMessage($message)
    Inherited, see "Internals" in Mail::Box

$obj->toBeThreaded($messages)
    Inherited, see "Internals" in Mail::Box

$obj->toBeUnthreaded($messages)
    Inherited, see "Internals" in Mail::Box

$obj->transporter( [$object] )
    Returns the object which is the interface to the IMAP4 protocol handler. The IMAP4 handler has the current folder selected. When an $object is specified, it is set to be the transporter from that moment on. The $object must extend Mail::Transport::IMAP4.

$obj->updateMessages(%options)
    Inherited, see "Internals" in Mail::Box

$obj->write(%options)
    The IMAP protocol usually writes the data immediately to the remote server, because that's what the protocol wants. However, some options to new() may delay that to boost performance. This method will, when the folder is being closed, write that info after all. Improves base, see "Internals" in Mail::Box

     -Option      --Defined in     --Default
      force         Mail::Box        false
      save_deleted  Mail::Box        false

    force => BOOLEAN
    save_deleted => BOOLEAN
$obj->writeMessages(%options)
    Inherited, see "Internals" in Mail::Box

     -Option     --Defined in     --Default
      messages     Mail::Box        <required>
      transporter                   <required>

    messages => ARRAY
    transporter => OBJECT

  Other methods
Extends "Other methods" in Mail::Box::Net.

$any->timespan2seconds($time)
    Inherited, see "Other methods" in Mail::Box

  Error handling
Extends "Error handling" in Mail::Box::Net.

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

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

  Cleanup
Extends "Cleanup" in Mail::Box::Net.

$obj->DESTROY()
    Inherited, see "Cleanup" in Mail::Box

DETAILS
Extends "DETAILS" in Mail::Box::Net.

DIAGNOSTICS

Warning: cannot find head back for $id in $folder.
    The header was read before, but now seems empty: the IMAP4 server does not produce the header lines anymore. Cast by getHeadAndBody()

Warning: cannot read body for $id in $folder.
    The header of the message was retrieved from the IMAP4 server, but the body is not read, for an unknown reason. Cast by getHeadAndBody()

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: copying failed for one message.
    For some reason, for instance disk full, removed by external process, or read-protection, it is impossible to copy one of the messages. Copying will proceed for the other messages. Cast by copyTo()

Error: couldn't select IMAP4 folder $name.
    Cast by transporter()

Error: destination folder $name is not writable.
    The folder where the messages are copied to is not opened with write access (see new(access)). This has no relation with write permission to the folder which is controlled by your operating system. Cast by copyTo()

Warning: different messages with id $msgid.
    The message id is discovered more than once within the same folder, but the content of the message seems to be different. This should not be possible: each message must be unique. Cast by messageId()

Warning: folder $name not deleted: not writable.
    The folder must be opened with write access via new(access), otherwise removing it will be refused. So, you may have write-access according to the operating system, but that will not automatically mean that this "delete" method permits you to. The reverse remark is valid as well. Cast by delete()

Notice: impossible to keep deleted messages in IMAP folder $name.
    Some folder type have a 'deleted' flag which can be stored in the folder to be performed later. The folder keeps that knowledge even when the folder is rewritten. Well, IMAP4 cannot play that trick. Cast by write()

Error: invalid timespan '$span'.
    The string does not follow the strict rules of the time span syntax which is permitted as parameter. Cast by timespan2seconds()

Warning: message $id disappeared from $folder.
    Trying to get the specific message from the server, but it appears to be gone. Cast by getHeadAndBody()

Warning: message {id} disappeared from {folder}.
    Trying to get the specific message from the server, but it appears to be gone. Cast by getHead()

Warning: message-id '$msgid' does not contain a domain.
    According to the RFCs, message-ids need to contain a unique random part, then an "@", and then a domain name. This is made to avoid the creation of two messages with the same id. The warning emerges when the "@" is missing from the string. Cast by messageId()

Error: no IMAP4 transporter configured.
    Cast by transporter()

Error: you cannot add a message which is already part of a folder to a new one.  Please use moveTo or copyTo.
    Cast by addMessage()

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.