
=head1 NAME

Mail::Transport::IMAP4 - proxy to Mail::IMAPClient


=head1 INHERITANCE

 Mail::Transport::IMAP4
   is a Mail::Transport::Receive
   is a Mail::Transport
   is a Mail::Reporter


=head1 SYNOPSIS

 my $imap = Mail::Transport::IMAP4->new(...);
 my $message = $imap->receive($id);
 $imap->send($message);


=head1 DESCRIPTION

****** UNDER DEVELOPMENT *****, please help testing

The IMAP4 protocol is quite complicated: it is feature rich and allows
verious asynchronous actions.  The main document describing IMAP is
rfc3501 (which obsoleted the original specification of protocol 4r1
in rfc2060 in March 2003).

This package, as part of MailBox, does not implement the actual
protocol itself but uses Mail::IMAPClient to do the work.  The task
for this package is to hide as many differences between that module's
interface and the common L<Mail::Box|Mail::Box> folder types.  Multiple
L<Mail::Box::IMAP4|Mail::Box::IMAP4> folders can share one L<Mail::Transport::IMAP4|Mail::Transport::IMAP4>
connection.



=head1 METHODS


$obj-E<gt>B<url>

=over 4

Represent this imap4 connection as URL.

=back

=head2 Constructors


Mail::Transport::IMAP4-E<gt>B<new>(OPTIONS)

=over 4

Create the IMAP connection to the server.  IMAP servers can handle
multiple folders for a single user, which means that connections
may get shared.  This is sharing is hidden for the user.

When an C<imap_client> is specified, then the options C<hostname>,
C<port>, C<username>, and C<password> are extracted from it.

 Option        Defined in       Default                             
 authenticate                   C<'AUTO'>                           
 domain                         <server_name>                       
 executable    L<Mail::Transport>  C<undef>                            
 hostname      L<Mail::Transport>  C<'localhost'>                      
 imap_client                    L<Mail::IMAPClient|Mail::IMAPClient>
 interval      L<Mail::Transport>  C<30>                               
 log           L<Mail::Reporter>  C<'WARNINGS'>                       
 password      L<Mail::Transport>  undef                               
 port          L<Mail::Transport>  143                                 
 proxy         L<Mail::Transport>  undef                               
 retry         L<Mail::Transport>  <false>                             
 timeout       L<Mail::Transport>  C<120>                              
 trace         L<Mail::Reporter>  C<'WARNINGS'>                       
 username      L<Mail::Transport>  undef                               
 via           L<Mail::Transport>  C<'imap'>                           

. authenticate TYPE|ARRAY-OF-TYPES

=over 4

Authenthication method to L<login()|Mail::Transport::IMAP4/"Protocol [internals]">, which will be passed to
L<Mail::IMAPClient> method authenticate().  See the latter method for
the available types.

=back

. domain WINDOWS_DOMAIN

=over 4

Used for NTLM authentication.

=back

. executable FILENAME

. hostname HOSTNAME|ARRAY-OF-HOSTNAMES

. imap_client OBJECT|CLASS

=over 4

When an OBJECT is supplied, that client will be used for the implementation
of the IMAP4 protocol. Information about server and such are extracted from
the OBJECT to have the accessors to produce correct results. The OBJECT
shall be a L<Mail::IMAPClient|Mail::IMAPClient>.

When a CLASS is given, an object of that type is created for you.  The created
object can be retreived via L<imapClient()|Mail::Transport::IMAP4/"Protocol [internals]">, and than configured as
defined by L<Mail::IMAPClient|Mail::IMAPClient>.

=back

. interval SECONDS

. log LEVEL

. password STRING

. port INTEGER

. proxy PATH

. retry NUMBER|undef

. timeout SECONDS

. trace LEVEL

. username STRING

. via CLASS|NAME

=back

=head2 Receiving mail


$obj-E<gt>B<receive>([UNIQUE-MESSAGE-ID])

=over 4

See L<Mail::Transport::Receive/"Receiving mail">

=back

=head2 Server connection


$obj-E<gt>B<findBinary>(NAME [, DIRECTORIES])

=over 4

See L<Mail::Transport/"Server connection">

=back

$obj-E<gt>B<remoteHost>

=over 4

See L<Mail::Transport/"Server connection">

=back

$obj-E<gt>B<retry>

=over 4

See L<Mail::Transport/"Server connection">

=back

=head2 Attributes


$obj-E<gt>B<authentication>(['AUTO'|TYPE|LIST-OF-TYPES])

=over 4

Returned is a list of pairs (ref arrays) each describing one possible
way to contact the server. Each pair contains a mechanism name and
a challange callback (which may be C<undef>).

The settings are used by L<login()|Mail::Transport::IMAP4/"Protocol [internals]"> to get server access.  The initial
value origins from L<new(authenticate)|Mail::Transport::IMAP4/"METHODS">, but may be changed later.

Available basic TYPES are C<CRAM-MD5> and C<PLAIN>.  The latter is sending
username and password in plain text, and is therefore tried as last
resort.

The C<NTLM> authentication requires Authen::NTLM to be installed.  Other
methods may be added later.  Besides, you may also specify a CODE
reference which implements some authentication.

When C<AUTO> is given, then C<CRAM-MD5>, C<NTLM> and C<PLAIN> are tried,
in that specific order.  When the Authen::NTLM is not installed it
will silently be skipped.  Be warned that, because of C<PLAIN>, erroneous
username/password combinations will be passed readible as last attempt!

An ARRAY as TYPE can be used to specify both mechanism as callback.  When
no array is used, callback of the pair is set to C<undef>.  See
L<Mail::IMAPCleint/authenticate> for the gory details.

I<Example:> 

 $transporter->authentication('CRAM-MD5', [MY_AUTH => \&c], 'PLAIN');

 foreach my $pair ($transporter->authentication)
 {   my ($mechanism, $challange) = @$pair;
     ...
 }

=back

$obj-E<gt>B<domain>([DOMAIN])

=over 4

Used in NTLM authentication to define the Windows domain which is
accessed.  Initially set by L<new(domain)|Mail::Transport::IMAP4/"METHODS"> and defaults to the
server's name.

=back

=head2 Exchanging Information


=head2 Protocol [internals]

The follow methods handle protocol internals, and should not be used
by a normal user of this class.

$obj-E<gt>B<appendMessage>(MESSAGE, FOLDERNAME)

=over 4

Write the message to the server.

=back

$obj-E<gt>B<createImapClient>(CLASS)

=over 4

Create an object of CLASS, which extends L<Mail::IMAPClient>.

=back

$obj-E<gt>B<destroyDeleted>

=over 4

Command the server to delete for real all messages which are flagged to
be deleted.

=back

$obj-E<gt>B<fetch>(ARRAY-OF-MESSAGES, INFO)

=over 4

Get some INFO about the MESSAGES from the server.  The specified messages
shall extend L<Mail::Box::Net::Message|Mail::Box::Net::Message>, Returned is a list
of hashes, each info about one result.  The contents of the hash
differs per INFO, but at least a C<message> field will be present, to
relate to the message in question.

The right folder should be selected before this method is called. When
the connection was lost, C<undef> is returned.  Without any
messages, and empty array is returned.  The retrieval is done by
L<Mail::IMAPClient|Mail::IMAPClient> method C<fetch()>, which is then
parsed.

=back

$obj-E<gt>B<flagsToLabels>(FLAGS)

Mail::Transport::IMAP4-E<gt>B<flagsToLabels>(FLAGS)

=over 4

In SCALAR context, a hash with labels is returned.  In LIST context, pairs
are returned.  Flags which do not appear in the list will be ignored: their
value may either by set or cleared.  See L<getFlags()|Mail::Transport::IMAP4/"Protocol [internals]">

Unknown flags in LIST are stripped from their backslash and lower-cased.
For instance, '\SomeWeirdFlag' will become `someweirdflag => 1'.

I<Example:> translating IMAP4 flags into MailBox flags


 my @flags  = ('\Seen', '\Flagged');
 my $labels = Mail::Transport::IMAP4->flags2labels(@flags);

=back

$obj-E<gt>B<folder>([FOLDERNAME])

=over 4

Be sure that the specific FOLDER is the current one selected.
If the folder is already selected, no IMAP traffic will be produced.
The imap connection is returned on succes

=back

$obj-E<gt>B<folders>([FOLDERNAME])

=over 4

Returns a list of folder names which are sub-folders of the specified
FOLDERNAME.  Without FOLDERNAME, the top-level foldernames are returned.

=back

$obj-E<gt>B<getFields>(UID, NAME, [NAME, ...])

=over 4

Get the records with the specified NAMES from the header.  The header
fields are returned as list of L<Mail::Message::Field::Fast|Mail::Message::Field::Fast> objects.
When the name is C<ALL>, the whole header is returned.

=back

$obj-E<gt>B<getFlags>(FOLDER, ID)

=over 4

Returns the values of all flags which are related to the message with the
specified ID.  These flags are translated into the names which are
standard for the MailBox suite.

A HASH is returned.  Names which do not appear will also provide
a value in the returned: the negative for the value is it was present.

=back

$obj-E<gt>B<getMessageAsString>(MESSAGE|UID)

=over 4

Returns the whole text of the specified message: the head and the body.

=back

$obj-E<gt>B<ids>

=over 4

Returns a list of UIDs which are defined by the IMAP server.

=back

$obj-E<gt>B<imapClient>

=over 4

Returns the object which implements the IMAP4 protocol, an instance
of a Mail::IMAPClient, which is logged-in and ready to use.

If the contact to the server was still present or could be established,
an Mail::IMAPClient object is returned.  Else, C<undef> is returned and
no further actions should be tried on the object.

=back

$obj-E<gt>B<labelsToFlags>(HASH|PAIRS)

Mail::Transport::IMAP4-E<gt>B<labelsToFlags>(HASH|PAIRS)

=over 4

Convert MailBox labels into IMAP flags.  Returned is a string.  Unsupported
labels are ignored.

=back

$obj-E<gt>B<login>

=over 4

Establish a new connection to the IMAP4 server, using username and password.

=back

$obj-E<gt>B<setFlags>(ID, LABEL, VALUE, [LABEL, VALUE], ...)

=over 4

Change the flags on the message which are represented by the label.  The
value which can be related to the label will be lost, because IMAP only
defines a boolean value, where MailBox labels can contain strings.

Returned is a list of LABEL=>VALUE pairs which could not be send to
the IMAP server.  These values may be cached in a different way.

=back

=head2 Error handling


$obj-E<gt>B<AUTOLOAD>

=over 4

See L<Mail::Reporter/"Error handling">

=back

$obj-E<gt>B<addReport>(OBJECT)

=over 4

See L<Mail::Reporter/"Error handling">

=back

$obj-E<gt>B<defaultTrace>([LEVEL, [LEVEL])

Mail::Transport::IMAP4-E<gt>B<defaultTrace>([LEVEL, [LEVEL])

=over 4

See L<Mail::Reporter/"Error handling">

=back

$obj-E<gt>B<errors>

=over 4

See L<Mail::Reporter/"Error handling">

=back

$obj-E<gt>B<log>([LEVEL [,STRINGS]])

Mail::Transport::IMAP4-E<gt>B<log>([LEVEL [,STRINGS]])

=over 4

See L<Mail::Reporter/"Error handling">

=back

$obj-E<gt>B<logPriority>(LEVEL)

Mail::Transport::IMAP4-E<gt>B<logPriority>(LEVEL)

=over 4

See L<Mail::Reporter/"Error handling">

=back

$obj-E<gt>B<logSettings>

=over 4

See L<Mail::Reporter/"Error handling">

=back

$obj-E<gt>B<notImplemented>

=over 4

See L<Mail::Reporter/"Error handling">

=back

$obj-E<gt>B<report>([LEVEL])

=over 4

See L<Mail::Reporter/"Error handling">

=back

$obj-E<gt>B<reportAll>([LEVEL])

=over 4

See L<Mail::Reporter/"Error handling">

=back

$obj-E<gt>B<trace>([LEVEL])

=over 4

See L<Mail::Reporter/"Error handling">

=back

$obj-E<gt>B<warnings>

=over 4

See L<Mail::Reporter/"Error handling">

=back

=head2 Cleanup


$obj-E<gt>B<DESTROY>

=over 4

The connection is cleanly terminated when the program is
terminated.

=back

$obj-E<gt>B<inGlobalDestruction>

=over 4

See L<Mail::Reporter/"Cleanup">

=back



=head1 DIAGNOSTICS

I<Error:> Cannot connect to $host:$port for IMAP4: $!


I<Error:> IMAP cannot connect to $host: $@


I<Notice:> IMAP4 authenication $mechanism to $host:$port successful


I<Error:> IMAP4 requires a username and password


I<Error:> IMAP4 username $username requires a password


I<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.

I<Error:> module Authen::NTLM is not installed

You try to establish an IMAP4 connection which explicitly uses NTLM
authentication, but the optional Authen::NTLM, which implements this is
not installed on your system.






=head1 REFERENCES

See the MailBox website at L<http://perl.overmeer.net/mailbox/> for more details.

=head1 COPYRIGHTS

Distribution version 2.056.
Written by Mark Overmeer (mark@overmeer.net).  See the ChangeLog for
other contributors.

Copyright (c) 2001-2003 by the author(s). All rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.


