Mail::Box::Maildir(3)

NAME
Mail::Box::Maildir - handle Maildir folders

INHERITANCE
 Mail::Box::Maildir
   is a Mail::Box::Dir
   is a Mail::Box
   is a Mail::Reporter

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

DESCRIPTION
This documentation describes how Maildir mailboxes work, and what you can do with the Maildir folder object "Mail::Box::Maildir".

Maildir is not supported for Windows, because it create filenames which are not accepted by the Windows system.

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

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

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::Dir.

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

$class->new(%options)
    Inherited, see "Constructors" in Mail::Box

     -Option           --Defined in     --Default
      accept_new                          false
      access             Mail::Box        'r'
      body_delayed_type  Mail::Box        Mail::Message::Body::Delayed
      body_type          Mail::Box        Mail::Message::Body::Lines
      coerce_options     Mail::Box        +[]
      create             Mail::Box        false
      directory          Mail::Box::Dir   <derived from folder name>
      extract            Mail::Box        10240
      field_type         Mail::Box        undef
      fix_headers        Mail::Box        false
      folder             Mail::Box        $ENV{MAIL}
      folderdir          Mail::Box        $ENV{HOME}/.maildir
      head_delayed_type  Mail::Box        Mail::Message::Head::Delayed
      head_type          Mail::Box        Mail::Message::Head::Complete
      keep_dups          Mail::Box        false
      lock_file          Mail::Box        <not used>
      lock_timeout       Mail::Box        <not used>
      lock_type          Mail::Box        'NONE' (constant)
      lock_wait          Mail::Box        <not used>
      locker             Mail::Box        undef
      manager            Mail::Box        undef
      message_type       Mail::Box        <folder-class>::Message
      multipart_type     Mail::Box        Mail::Message::Body::Multipart
      remove_when_empty  Mail::Box        true
      save_on_exit       Mail::Box        true
      trusted            Mail::Box        <depends on folder location>

    accept_new => BOOLEAN
        When the folder is open, some messages may be stored in the "new" sub-directory. By default, these messages are immediately moved to the "cur" directory when the folder is opened. Otherwise, you have to call acceptMessages() or Mail::Box::Maildir::Message::accept().

    access => $mode
    body_delayed_type => CLASS
    body_type => CLASS|CODE
    coerce_options => ARRAY
    create => BOOLEAN
    directory => $directory
    extract => INTEGER|CODE|METHOD|'LAZY'|'ALWAYS'
    field_type => $class
    fix_headers => BOOLEAN
    folder => $name
    folderdir => $directory
    head_delayed_type => $class
    head_type => $class
    keep_dups => BOOLEAN
    lock_file => $file
    lock_timeout => $seconds
    lock_type => $class|$name|\@names
    lock_wait => $seconds
    locker => $locker
    manager => $manager
    message_type => $class
    multipart_type => CLASS
    remove_when_empty => BOOLEAN
    save_on_exit => BOOLEAN
    trusted => BOOLEAN

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

$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::Dir.

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

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

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

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

$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::Dir.

$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::Dir.

$obj->current( [$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::Dir.

$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::Dir.

$obj->acceptMessages()
    Accept all messages which are waiting in the "new" directory to be moved to the "cur" directory. This will not rescan the directory for newly arrived messages, because that's a task for update().

$class->appendMessage(%options)

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

$any->create($foldername, %options)
    [4.000] Returns the created directory. Improves base, see "Internals" in Mail::Box

     -Option   --Defined in--Default
      folderdir  Mail::Box   undef

    folderdir => $directory
$any->createDirs($folderdir)
    The $folderdir contains the absolute path of the location where the messages are kept. Maildir folders contain a "tmp", "new", and "cur" sub-directory within that folder directory as well. This method will ensure that all directories exist. Returns "false" on failure.

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

$any->folderIsEmpty($folderdir)
    Checks whether the folder whose directory is specified as absolute $folderdir is empty or not. A folder is empty when the "tmp", "new", and "cur" subdirectories are empty and some files which are left there by application programs. The maildir spec explicitly states: ".qmail", "bulletintime", "bulletinlock" and "seriallock". If any other files are found, the directory is considered not-empty.

$obj->folderToDirectory($foldername, $folderdir)
    Inherited, see "Internals" in Mail::Box::Dir

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

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

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

$obj->messageInFile($filename)
    Inherited, see "Internals" in Mail::Box::Dir

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

$obj->readMessageFilenames($directory)
    Inherited, see "Internals" in Mail::Box::Dir

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

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

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

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

    messages => ARRAY

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

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

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

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

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

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

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

DETAILS
The explanation is complicated, but for normal use you should bother yourself with all details.

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

  Different kinds of folders
Extends "Different kinds of folders" in Mail::Box::Dir.

  Available folder types
Extends "Available folder types" in Mail::Box::Dir.

  Folder class implementation
Extends "Folder class implementation" in Mail::Box::Dir.

  How MAILDIR folders work
Maildir-type folders use a directory to store the messages of one folder. Each message is stored in a separate file. This seems useful, because changes in a folder change only a few of these small files, in contrast with file-based folders where changes in a folder cause rewrites of huge folder-files.

However, Maildir based folders perform very bad if you need header information of all messages. For instance, if you want to have full knowledge about all message-threads (see Mail::Box::Thread::Manager) in the folder, it requires to read all header lines in all message files. And usually, reading your messages as threads is desired. Maildir maintains a tiny amount of info visible in the filename, which may make it perform just a little bit faster than MH.

DIAGNOSTICS

Error: Cannot append Maildir message in $new to folder $self.
    The message (or messages) could not be stored in the right directories for the Maildir folder. Cast by appendMessage()

Error: Cannot create Maildir message file $new.
    A message is converted from some other message format into a Maildir format by writing it to a file with a name which contains the status flags of the message. Apparently, creating this file failed. Cast by coerce()

Fault: Cannot create directory $dir: $!
    Cast by appendMessage()

Error: Folder $name is opened read-only
    You can not write to this folder unless you have opened the folder to write or append with new(access), or the "force" option is set "true". Cast by write()

Fault: cannot create Maildir directory $dir: $!
    A Maildir folder is represented by a directory, with some sub-directories. The top folder directory could not be created for the reason indicated. Cast by createDirs()

Fault: cannot create Maildir subdir $dir: $!
    Each Maildir folder has three sub-directories for administration: "new", "tmp", and "cur". The mentioned directory could not be created for the indicated reason. Cast by createDirs()

Fault: cannot create directory $dir: $!
    Cast by writeMessages()

Fault: cannot create file $file: $!
    Cast by writeMessages()

Fault: cannot rename $from to $to: $!
    Cast by writeMessages()

Warning: changes not written to read-only folder $name.
    You have opened the folder read-only --which is the default set by new(access)--, made modifications, and now want to close it. Set close(force) if you want to overrule the access mode, or close the folder with close(write) set to "NEVER". Cast by close()

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: 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()

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 '$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 locking possible for maildir folders.
    Cast by new()

Error: unknown value to folder->close(write => $when).
    Cast by close()

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 version 4.02, built on April 10, 2026. Website: http://perl.overmeer.net/CPAN/

LICENSE
For contributors see file ChangeLog.

This software is copyright (c) 2001-2026 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.