NAME

Mail::Box::Mbox - handle folders in Mbox format

INHERITANCE

Mail::Box::Mbox
  is a Mail::Box::File
  is a Mail::Box
  is a Mail::Reporter

SYNOPSIS

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

DESCRIPTION

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

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

OVERLOADED

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

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::File.

Constructors

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

$class->new(%options)

Inherited, 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::File  <see description>
 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        $ENV{MAIL}
 folderdir            Mail::Box        $ENV{HOME}.'/Mail'
 head_delayed_type    Mail::Box        Mail::Message::Head::Delayed
 head_type            Mail::Box        Mail::Message::Head::Complete
 keep_dups            Mail::Box        false
 lock_extension       Mail::Box::File  '.lock'
 lock_file            Mail::Box        <foldername><lock-extension>
 lock_timeout         Mail::Box        1 hour
 lock_type            Mail::Box        Mail::Box::Locker::DotLock
 lock_wait            Mail::Box        10 seconds
 locker               Mail::Box        undef
 log                  Mail::Reporter   'WARNINGS'
 manager              Mail::Box        undef
 message_type         Mail::Box        Mail::Box::Mbox::Message
 multipart_type       Mail::Box        Mail::Message::Body::Multipart
 remove_when_empty    Mail::Box        true
 save_on_exit         Mail::Box        true
 subfolder_extension                   '.d'
 trace                Mail::Reporter   'WARNINGS'
 trusted              Mail::Box        <depends on folder location>
 write_policy         Mail::Box::File  undef
access => $mode
body_delayed_type => CLASS
body_type => CLASS|CODE
coerce_options => ARRAY
create => BOOLEAN
extract => INTEGER | CODE | METHOD | 'LAZY'| 'ALWAYS'
field_type => CLASS
fix_headers => BOOLEAN
folder => FOLDERNAME
folderdir => $directory
head_delayed_type => CLASS
head_type => CLASS
keep_dups => BOOLEAN
lock_extension => $file|STRING
lock_file => $file
lock_timeout => $seconds
lock_type => CLASS|STRING|ARRAY
lock_wait => $seconds
locker => OBJECT
log => LEVEL
manager => $manager
message_type => CLASS
multipart_type => CLASS
remove_when_empty => BOOLEAN
save_on_exit => BOOLEAN
subfolder_extension => STRING

Mbox folders do not support sub-folders. However, this module can simulate sub-directories if the user wants it to. When a subfolder of folder xyz is created, we create a directory which is called xyz.d to contain them. This extension .d can be changed using this option.

trace => LEVEL
trusted => BOOLEAN
write_policy => 'REPLACE'|'INPLACE'|undef

Attributes

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

$obj->filename()

Inherited, see "Attributes" in Mail::Box::File

$obj->fixHeaders()

Inherited, see "Attributes" in Mail::Box

$obj->folderdir( [$directory] )

Inherited, see "Attributes" in Mail::Box

$class->foundIn( [$foldername], %options )

If no $foldername is specified, then the value of the folder option is taken. A mbox folder is a file which starts with a separator line: a line with 'From ' as first characters. Blank lines which start the file are ignored, which is not for all MUA's acceptable. Improves base, see "Internals" in Mail::Box

-Option             --Defined in     --Default
 folder                                undef
 folderdir            Mail::Box        undef
 subfolder_extension                   <from object>
folder => $name
folderdir => $directory
subfolder_extension => STRING
$obj->isTrusted()

Inherited, see "Attributes" in Mail::Box

$any->listSubFolders(%options)

Inherited, see "Sub-folders" in Mail::Box

-Option             --Defined in     --Default
 check                Mail::Box        <C<false>>
 folder               Mail::Box        <from calling object>
 folderdir            Mail::Box        <from folder>
 skip_empty           Mail::Box        <C<false>>
 subfolder_extension                   <from object>
check => BOOLEAN
folder => FOLDERNAME
folderdir => DIRECTORY
skip_empty => BOOL
subfolder_extension => STRING

When the method is called on an open folder, the extension defined by it is used to detect sub-folders by default. Otherwise, '.d' is taken.

$obj->logSettings()

Inherited, see "Attributes" in Mail::Reporter

$obj->name()

Inherited, see "Attributes" in Mail::Box

$obj->removeEmpty()

Inherited, see "Attributes" in Mail::Box

$obj->subfolderExtension()

$obj->type()

Inherited, see "Attributes" in Mail::Box

The folder

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

$obj->addMessage($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::File

$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->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::File.

$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::File.

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

$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::File.

$obj->coerce($message, %options)

Inherited, see "Internals" in Mail::Box

$any->create($foldername, %options)

Inherited, see "Internals" in Mail::Box

-Option             --Defined in     --Default
 folderdir            Mail::Box        undef
 subfolder_extension                   undef
folderdir => $directory
subfolder_extension => STRING

If a directory is found on the location of the folder to be created, this STRING is used to extend that directory name with. This will cause the directory to be seen as sub-folder for the created folder. This argument is passed to folderToFilename().

$obj->determineBodyType($message, $head)

Inherited, see "Internals" in Mail::Box

$any->folderToFilename( $foldername, $folderdir, [$extension] )

Translate a folder name into a filename, using the $folderdir value to replace a leading =. If no $extension is specified and this method is called as instance method, new(subfolder_extension) is used. Otherwise, the extension default to '.d'. Improves base, see "Internals" in Mail::Box::File

$obj->lineSeparator( [<STRING|'CR'|'LF'|'CRLF'>] )

Inherited, see "Internals" in Mail::Box

$obj->locker()

Inherited, see "Internals" in Mail::Box

$obj->messageCreateOptions( [$type, $config] )

Inherited, see "Internals" in Mail::Box::File

$obj->moveAwaySubFolder($directory, $extension)

Inherited, see "Internals" in Mail::Box::File

$obj->parser()

Inherited, see "Internals" in Mail::Box::File

$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->updateMessages(%options)

Inherited, see "Internals" in Mail::Box::File

$obj->write(%options)

Inherited, see "Internals" in Mail::Box::File

$obj->writeMessages(%options)

Inherited, see "Internals" in Mail::Box

Other methods

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

$any->timespan2seconds($time)

Inherited, see "Other methods" in Mail::Box

Error handling

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

$obj->AUTOLOAD()

Inherited, see "Error handling" in Mail::Reporter

$obj->addReport($object)

Inherited, see "Error handling" in Mail::Reporter

$any->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )

Inherited, see "Error handling" in Mail::Reporter

$obj->errors()

Inherited, see "Error handling" in Mail::Reporter

$any->log( [$level, [$strings]] )

Inherited, see "Error handling" in Mail::Reporter

$any->logPriority($level)

Inherited, see "Error handling" in Mail::Reporter

$obj->notImplemented()

Inherited, see "Error handling" in Mail::Reporter

$obj->report( [$level] )

Inherited, see "Error handling" in Mail::Reporter

$obj->reportAll( [$level] )

Inherited, see "Error handling" in Mail::Reporter

$obj->trace( [$level] )

Inherited, see "Error handling" in Mail::Reporter

$obj->warnings()

Inherited, see "Error handling" in Mail::Reporter

Cleanup

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

$obj->DESTROY()

Inherited, see "Cleanup" in Mail::Box

DETAILS

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

DETAILS

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

Different kinds of folders

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

Available folder types

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

Folder class implementation

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

How MBOX folders work

MBOX folders store many messages in one file. Each message begins with a line which starts with the string From . Lines inside a message which accidentally start with From are, in the file, preceded by `>'. This character is stripped when the message is read.

In this respect must be noted that the format of the MBOX files is not strictly defined. The exact content of the separator lines differ between Mail User Agents (MUA's). Besides, some MUAs (like mutt) forget to encode the From lines within message bodies, breaking other parsers....

Simulation of sub-folders

MBOX folders do not have a sub-folder concept as directory based folders do, but this MBOX module tries to simulate them. In this implementation a directory like

Mail/subject1/

is taken as an empty folder Mail/subject1, with the folders in that directory as sub-folders for it. You may also use

Mail/subject1
Mail/subject1.d/

where Mail/subject1 is the folder, and the folders in the Mail/subject1.d directory are used as sub-folders. If your situation is similar to the first example and you want to put messages in that empty folder, the directory is automatically (and transparently) renamed, so that the second situation is reached.

DIAGNOSTICS

Error: Cannot append messages to folder file $filename: $!

Appending messages to a not-opened file-organized folder may fail when the operating system does not allow write access to the file at hand. Cast by appendMessages()

Error: Cannot move away sub-folder $dir

Cast by moveAwaySubFolder()

Warning: Cannot remove folder $name file $filename: $!

Writing an empty folder will usually cause that folder to be removed, which fails for the indicated reason. new(remove_when_empty) Cast by write()

Warning: Cannot remove folder $name file $filename: $!

Writing an empty folder will usually cause that folder to be removed, which fails for the indicated reason. new(remove_when_empty) controls whether the empty folder will removed; setting it to false (0) may be needed to avoid this message. Cast by write()

Error: Cannot replace $filename by $tempname, to update folder $name: $!

The replace policy wrote a new folder file to update the existing, but was unable to give the final touch: replacing the old version of the folder file for the indicated reason. Cast by write()

Warning: Changes not written to read-only folder $self.

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: 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. 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()

Error: File too short to get write message $nr ($size, $need)

Mail::Box is lazy: it tries to leave messages in the folders until they are used, which saves time and memory usage. When this message appears, something is terribly wrong: some lazy message are needed for updating the folder, but they cannot be retrieved from the original file anymore. In this case, messages can be lost.

This message does appear regularly on Windows systems when using the 'replace' write policy. Please help to find the cause, probably something to do with Windows incorrectly handling multiple filehandles open in the same file. Cast by write()

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. Cast by delete()

Error: Invalid timespan '$timespan' specified.

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: 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. Cast by notImplemented()

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. Cast by copyTo()

Error: Unable to update folder $self.

When a folder is to be written, both replace and inplace write policies are tried, If both fail, the whole update fails. You may see other, related, error messages to indicate the real problem. Cast by write()

SEE ALSO

This module is part of Mail-Box version 3.012, built on November 27, 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.