Provided by: libmail-box-pop3-perl_3.005-2_all bug

NAME

       Mail::Box::POP3 - handle POP3 folders as client

INHERITANCE

        Mail::Box::POP3
          is a Mail::Box::Net
          is a Mail::Box
          is a Mail::Reporter

        Mail::Box::POP3 is extended by
          Mail::Box::POP3s

SYNOPSIS

        use Mail::Box::POP3;
        my $folder = Mail::Box::POP3->new(folder => $ENV{MAIL}, ...);

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 POP3 protocol.
       This class uses Mail::Transport::POP3 to hide the transport of information, and focusses
       solely on the correct handling of messages within a POP3 folder.

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

OVERLOADED

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

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

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

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

METHODS

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

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

       Mail::Box::POP3->new(%options)
           For authentications, you have three choices: specify a foldername which resembles an
           URL, or specify a pop-client object, or separate options for user, password, pop-
           server and server-port.

            -Option           --Defined in     --Default
             access             Mail::Box        'r'
             authenticate                        'AUTO'
             body_delayed_type  Mail::Box        Mail::Message::Body::Delayed
             body_type          Mail::Box        Mail::Message::Body::Lines
             coerce_options     Mail::Box        []
             create             Mail::Box        <not applicable>
             extract            Mail::Box        10240
             field_type         Mail::Box        undef
             fix_headers        Mail::Box        <false>
             folder             Mail::Box        <not applicable>
             folderdir          Mail::Box        <network location>
             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        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::POP3::Message
             multipart_type     Mail::Box        Mail::Message::Body::Multipart
             password           Mail::Box::Net   undef
             pop_client                          undef
             remove_when_empty  Mail::Box        <false>
             save_on_exit       Mail::Box        <true>
             server_name        Mail::Box::Net   undef
             server_port        Mail::Box::Net   110
             trace              Mail::Reporter   'WARNINGS'
             trusted            Mail::Box        <false>
             username           Mail::Box::Net   undef

           access => MODE
           authenticate => 'LOGIN'|'APOP'|'AUTO'
             POP3 can use two methods of authentication: the old LOGIN protocol, which transmits
             a username and password in plain text, and the newer APOP protocol which uses MD5
             encryption.  APOP is therefore much better, however not always supported by the
             server.  With AUTO, first APOP is tried and if that fails LOGIN.

           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_file => FILENAME
           lock_timeout => SECONDS
           lock_type => CLASS|STRING|ARRAY
           lock_wait => SECONDS
           locker => OBJECT
           log => LEVEL
           manager => MANAGER
           message_type => CLASS
           multipart_type => CLASS
           password => STRING
           pop_client => OBJECT
             You may want to specify your own pop-client object.  The object which is passed must
             extend Mail::Transport::POP3.

           remove_when_empty => BOOLEAN
           save_on_exit => BOOLEAN
           server_name => HOSTNAME
           server_port => INTEGER
           trace => LEVEL
           trusted => BOOLEAN
           username => STRING

           example:

            my $url = 'pop3://user:password@pop.xs4all.nl'
            my $pop = Mail::Box::POP3->new($url);

            my $pop = $mgr->open(type => 'pop3',
               username => 'myname', password => 'mypassword',
               server_name => 'pop.xs4all.nl');

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

       $obj->addMessage($message)
           It is impossible to write messages to the average POP3 server.  There are extensions
           to the protocol which do permit it, however these are not implemented (yet, patches
           welcome).

           "undef" is returned, and an error displayed.  However, no complaint is given when the
           $message is "undef" itself.

            -Option--Defined in--Default
             share   Mail::Box   <not used>

           share => BOOLEAN
       $obj->addMessages($messages)
           As useless as addMessage().  The only acceptable call to this method is without any
           message.

       Mail::Box::POP3->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)
           It is not possible to delete a POP3 folder remotely: the best we can do is remove all
           the messages in it... which is the action implemented here.  A notice is logged about
           this.

            -Option   --Defined in--Default
             recursive  Mail::Box   <not used>

           recursive => BOOLEAN
       $obj->folderdir( [$directory] )
           Inherited, see "The folder" in Mail::Box

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

       $obj->update()
           NOT IMPLEMENTED YET

       $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.

       $obj->listSubFolders(%options)
       Mail::Box::POP3->listSubFolders(%options)
           The standard POP3 protocol does not support sub-folders, so an empty list will be
           returned in any case.

            -Option    --Defined in     --Default
             check       Mail::Box        <false>
             folder      Mail::Box        <from calling object>
             folderdir   Mail::Box        <from folder>
             skip_empty  Mail::Box        <false>

           check => BOOLEAN
           folder => FOLDERNAME
           folderdir => DIRECTORY
           skip_empty => BOOL
       $obj->nameOfSubFolder( $subname, [$parentname] )
       Mail::Box::POP3->nameOfSubFolder( $subname, [$parentname] )
           Inherited, see "Sub-folders" in Mail::Box

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

       $obj->openSubFolder(%options)
           It is not possible to open a sub-folder for a POP3 folder, because that is not
           supported by the official POP3 protocol. In any case, "undef" is returned to indicate
           a failure.

       $obj->topFolderWithMessages()
       Mail::Box::POP3->topFolderWithMessages()
           Inherited, see "Sub-folders" in Mail::Box

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

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

       $obj->create($folder, %options)
       Mail::Box::POP3->create($folder, %options)
           It is not possible to create a new folder on a POP3 server.  This method will always
           return "false".

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

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

       Mail::Box::POP3->foundIn( [$foldername], %options )
           Inherited, see "Internals" in Mail::Box

       $obj->getHead($message)
           Read the header for the specified message from the remote server.

       $obj->getHeadAndBody($message)
           Read all data for the specified message from the remote server.

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

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

       $obj->popClient(%options)
           Returns the pop client object.  This does not establish the connection.

            -Option --Default
             use_ssl  <false>

           use_ssl => BOOLEAN
       $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

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

       $obj->writeMessages(%options)
            -Option  --Defined in--Default
             messages  Mail::Box   <required>

           messages => ARRAY

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

       $obj->timespan2seconds($time)
       Mail::Box::POP3->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

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

       $obj->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
       Mail::Box::POP3->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
           Inherited, see "Error handling" in Mail::Reporter

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

       $obj->log( [$level, [$strings]] )
       Mail::Box::POP3->log( [$level, [$strings]] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->logPriority($level)
       Mail::Box::POP3->logPriority($level)
           Inherited, see "Error handling" in Mail::Reporter

       $obj->logSettings()
           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::Net.

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

DETAILS

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

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

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

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

   How POP3 folders work
       Rfc1939 defines how POP3 works.  POP3 is a really simple protocol to receive messages from
       a server to a user's client.  POP3 is also really limited: it can only be used to fetch
       messages, but has not many ways to limit the amount of network traffic, like the IMAP4
       protocol has.

       One POP3 account represents only one folder: there is no way of sub-folders in POP3.  POP3
       doesn't support writing (except for some message status flags).

   This implementation
       The protocol specifics are implemented in Mail::Transport::POP3, written by Liz Mattijsen.
       That module does not use any of the other POP3 modules available on CPAN for the reason
       that MailBox tries to be smarter: it is capable of re-establishing broken POP3 connection
       when the server supports UIDs.

       The implementation has shown to work with many different POP servers.  In the test
       directory of the distribution, you will find a small server implementation, which is used
       to test the client.

DIAGNOSTICS

       Error: Cannot create POP3 client for $name.
           The connection to the POP3 server cannot be established.  You may see more, related,
           error messages about the failure.

       Error: Cannot find head back for $uidl on POP3 server $name.
           The server told to have this message, but when asked for its headers, no single line
           was returned.  Did the message get destroyed?

       Error: Cannot read body for $uidl on POP3 server $name.
           The message's headers are retrieved from the server, but the body seems to be lost.
           Did the message get destroyed between reading the header and reading the body?

       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".

       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: 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.

       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 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.

       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 on POP3 server $name disappeared.
           The server indicated the existence of this message before, however it has no
           information about the message anymore.

       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.

       Warning: POP3 folders cannot be deleted.
           Each user has only one POP3 folder on a server.  This folder is created and deleted by
           the server's administrator only.

       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.

       Error: Update of $nr messages ignored for POP3 folder $name.
           The standard POP3 implementation does not support writing from client back to the
           server.  Therefore, modifications may be lost.

       Error: Writing folder $name failed
           For some reason (you probably got more error messages about this problem) it is
           impossible to write the folder, although you should because there were changes made.

       Error: You cannot write a message to a pop server (yet)
           Some extensions to the POP3 protocol do permit writing messages to the server, but the
           standard protocol only implements retreival.  Feel invited to extend our
           implementation with writing.

SEE ALSO

       This module is part of Mail-Box-POP3 distribution version 3.005, built on May 03, 2019.
       Website: http://perl.overmeer.net/CPAN/

LICENSE

       Copyrights 2001-2019 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 http://dev.perl.org/licenses/