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Module Version: 2.107   Source   Latest Release: Mail-Box-2.120


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


   is a Mail::Box::Net
   is a Mail::Box
   is a Mail::Reporter


 use Mail::Box::IMAP4;
 my $folder = Mail::Box::IMAP4->new(folder => $ENV{MAIL}, ...);


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.

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.


overload: ""()

See "OVERLOADED" in Mail::Box

overload: @{}()

See "OVERLOADED" in Mail::Box

overload: cmp()

See "OVERLOADED" in Mail::Box




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.

 -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        <not used>
  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
  log                Mail::Reporter   'WARNINGS'
  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
  trace              Mail::Reporter   'WARNINGS'
  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 wether that body object can be reused or not. NO means: retreive 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
field_type => CLASS
fix_headers => BOOLEAN
folder => FOLDERNAME
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 => FILENAME
lock_timeout => SECONDS
lock_wait => SECONDS
locker => OBJECT
log => LEVEL
manager => MANAGER
message_type => CLASS
multipart_type => CLASS
password => STRING
remove_when_empty => BOOLEAN
save_on_exit => BOOLEAN
server_name => HOSTNAME
server_port => INTEGER
trace => LEVEL
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 => STRING


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

 my $url    = 'imap4://');
 my $imap   = $mgr->open($url);

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

The folder

$obj->addMessage(MESSAGE, OPTIONS)

See "The folder" in Mail::Box

$obj->addMessages(MESSAGE [, MESSAGE, ...])

See "The folder" in Mail::Box


See "The folder" in Mail::Box


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()

 -Option      --Defined in     --Default
  force         Mail::Box        <false>
  save_deleted  Mail::Box        false
  write         Mail::Box        MODIFIED
force => BOOLEAN
save_deleted => BOOLEAN
$obj->copyTo(FOLDER, OPTIONS)

See "The folder" in Mail::Box


See "The folder" in Mail::Box


See "METHODS" in Mail::Box::Net


See "The folder" in Mail::Box


See "The folder" in Mail::Box


See "The folder" in Mail::Box


See "The folder" in Mail::Box


See "The folder" in Mail::Box


See "The folder" in Mail::Box

Folder flags


See "Folder flags" in Mail::Box


See "Folder flags" in Mail::Box


See "Folder flags" in Mail::Box


See "Folder flags" in Mail::Box

The messages


See "The messages" in Mail::Box


See "The messages" in Mail::Box

$obj->findFirstLabeled(LABEL, [BOOLEAN, [ARRAY-OF-MSGS]])

See "The messages" in Mail::Box

$obj->message(INDEX [,MESSAGE])

See "The messages" in Mail::Box

$obj->messageId(MESSAGE-ID [,MESSAGE])

See "The messages" in Mail::Box


See "The messages" in Mail::Box


See "The messages" in Mail::Box


See "The messages" in Mail::Box


See "The messages" in Mail::Box



See "Sub-folders" in Mail::Box

$obj->nameOfSubFolder(SUBNAME, [PARENTNAME])
Mail::Box::IMAP4->nameOfSubFolder(SUBNAME, [PARENTNAME])

See "Sub-folders" in Mail::Box


See "Sub-folders" in Mail::Box

$obj->openSubFolder(SUBNAME, OPTIONS)

See "Sub-folders" in Mail::Box


See "Sub-folders" in Mail::Box


$obj->coerce(MESSAGE, OPTIONS)

See "Internals" in Mail::Box

$obj->create(FOLDER, OPTIONS)
Mail::Box::IMAP4->create(FOLDER, OPTIONS)

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)

See "Internals" in Mail::Box


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.

Mail::Box::IMAP4->foundIn([FOLDERNAME], OPTIONS)

See "Internals" in Mail::Box


Read the header for the specified message from the remote server. undef is returned in case the message disappeared.


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.


See "Internals" in Mail::Box


See "Internals" in Mail::Box


See "Internals" in Mail::Box


See "Internals" in Mail::Box


See "Internals" in Mail::Box


See "Internals" in Mail::Box


See "Internals" in Mail::Box


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.


See "Internals" in Mail::Box


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.

 -Option      --Defined in     --Default
  force         Mail::Box        <false>
  save_deleted                   <false>
force => BOOLEAN
save_deleted => BOOLEAN

You may be able to save the messages which are flagged for deletion now, but they will be removed anyway when the folder is closed.

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

Other methods


See "Other methods" in Mail::Box

Error handling


See "Error handling" in Mail::Reporter


See "Error handling" in Mail::Reporter


See "Error handling" in Mail::Reporter


See "Error handling" in Mail::Reporter

$obj->log([LEVEL [,STRINGS]])
Mail::Box::IMAP4->log([LEVEL [,STRINGS]])

See "Error handling" in Mail::Reporter


See "Error handling" in Mail::Reporter


See "Error handling" in Mail::Reporter


See "Error handling" in Mail::Reporter


See "Error handling" in Mail::Reporter


See "Error handling" in Mail::Reporter


See "Error handling" in Mail::Reporter


See "Error handling" in Mail::Reporter



See "Cleanup" in Mail::Box


See "Cleanup" in Mail::Reporter


Warning: Cannot find head back for $uidl in $folder.

The header was read before, but now seems empty: the IMAP4 server does not produce the header lines anymore.

Warning: Cannot read body for $uidl in $folder.

The header of the message was retreived from the IMAP4 server, but the body is not read, for an unknown reason.

Error: Copying failed for one message.

For some reason, for instance disc full, removed by external process, or read-protection, it is impossible to copy one of the messages. Copying will proceed for the other messages.

Error: Couldn't select IMAP4 folder $name
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 controled by your operating system.

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.

Error: 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.

Notice: Impossible to keep deleted messages in IMAP

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.

Error: Invalid timespan '$timespan' specified.

The string does not follow the strict rules of the time span syntax which is permitted as parameter.

Warning: Message $uidl disappeared from $folder.

Trying to get the specific message from the server, but it appears to be gone.

Warning: Message $uidl disappeared from $folder.

Trying to get the specific message from the server, but it appears to be gone.

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.

Error: No IMAP4 transporter configured
Error: Package $package does not implement $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.

Error: Unable to create subfolder $name of $folder.

The copy includes the subfolders, but for some reason it was not possible to copy one of these. Copying will proceed for all other sub-folders.


This module is part of Mail-Box distribution version 2.107, built on November 28, 2012. Website:


Copyrights 2001-2012 by [Mark Overmeer]. For other contributors see ChangeLog.

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

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