Mail::Transport::POP3(3) receive messages via POP3


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


my $receiver = Mail::Transport::POP3->new(...);
my $message = $receiver->receive($id);


Receive messages via the POP3 protocol from one remote server, as specified in rfc1939. This object hides much of the complications in the protocol and recovers broken connections automatically. Although it is part of the MailBox distribution, this object can be used separately.

You probably should not use this module, but Mail::Box::POP3. This module is the interface to POP3, whereas Mail::Box::POP3 hides the protocol weirdness and works as any other mail folder.

Extends ``DESCRIPTION'' in Mail::Transport::Receive.


Extends ``METHODS'' in Mail::Transport::Receive.


Extends ``Constructors'' in Mail::Transport::Receive.
Create a new pop3 server connection. One object can only handle one connection: for a single user to one single server. If the server could not be reached, or when the login fails, this instantiating "new" will return "undef".

 -Option      --Defined in     --Default
  authenticate                   'AUTO'
  executable    Mail::Transport  undef
  hostname      Mail::Transport  'localhost'
  interval      Mail::Transport  30
  log           Mail::Reporter   'WARNINGS'
  password      Mail::Transport  undef
  port          Mail::Transport  110
  proxy         Mail::Transport  undef
  retry         Mail::Transport  <false>
  timeout       Mail::Transport  120
  trace         Mail::Reporter   'WARNINGS'
  use_ssl                        <false>
  username      Mail::Transport  undef
  via           Mail::Transport  'sendmail'
authenticate => 'LOGIN'|'APOP'|'AUTO'
Authenthication method. The standard defines two methods, named LOGIN and APOP. The first sends the username and password in plain text to the server to get permission, the latter encrypts this data using MD5. When AUTO is used, first APOP is tried, and then LOGIN.
executable => FILENAME
hostname => HOSTNAME|ARRAY
interval => SECONDS
log => LEVEL
password => STRING
port => INTEGER
proxy => PATH
retry => NUMBER|undef
timeout => SECONDS
trace => LEVEL
use_ssl => BOOLEAN
username => STRING

Receiving mail

Extends ``Receiving mail'' in Mail::Transport::Receive.
$obj->receive( [$unique_message_id] )
Inherited, see ``Receiving mail'' in Mail::Transport::Receive

Exchanging information

Mark all messages that have been fetched with message() for deletion. See fetched().
$obj->deleted(BOOLEAN, @ids)
Either mark the specified message(s) to be deleted on the remote server or unmark them for deletion (if the first parameter is false). Deletion of messages will take place only when the connection is specifically disconnected or the last reference to the object goes out of scope.
Break contact with the server, if that (still) exists. Returns true if successful. Please note that even if the disconnect was not successful, all knowledge of messages etc. will be removed from the object: the object basically has reverted to the state in which it was before anything was done with the mail box.
Returns a reference to a list of ID's that have been fetched using message(). This can be used to update a database of messages that were fetched (but maybe not yet deleted) from the mailbox.

Please note that if the POP3 server did not support the UIDL command, this method will always return undef because it is not possibly to reliably identify messages between sessions (other than looking at the contents of the messages themselves).

See also deleteFetched().

Returns the total number of octets used by the mailbox on the remote server.
$obj->header( $id, [$bodylines] )
Returns a reference to an array which contains the header of the message with the specified $id. "undef" is returned if something has gone wrong.

The optional integer $bodylines specifies the number of lines from the body which should be added, by default none.


 my $ref_lines = $pop3->header($uidl);
 print @$ref_lines;
Translates the unique $id of a message into a sequence number which represents the message as long a this connection to the POP3 server exists. When the message has been deleted for some reason, "undef" is returned.
Returns a list (in list context) or a reference to a list (in scalar context) of all IDs which are known by the server on this moment.
Returns a reference to an array which contains the lines of the message with the specified $id. Returns "undef" if something has gone wrong.


 my $ref_lines = $pop3->message($uidl);
 print @$ref_lines;
Returns the size of the message which is indicated by the $id, in octets. If the message has been deleted on the remote server, this will return "undef".
Returns (in scalar context only) the number of messages that are known to exist in the mailbox.

Protocol internals

The follow methods handle protocol internals, and should not be used by a normal user of this class.
Establish a new connection to the POP3 server, using username and password.
$obj->send($socket, $data)
Send $data to the indicated socket and return the first line read from that socket. Logs an error if either writing to or reading from socket failed.

This method does not attempt to reconnect or anything: if reading or writing the socket fails, something is very definitely wrong.

$obj->sendList($socket, $command)
Sends the indicated $command to the specified socket, and retrieves the response. It returns a reference to an array with all the lines that were reveived after the first "+OK" line and before the end-of-message delimiter (a single dot on a line). Returns "undef" whenever something has gone wrong.
Returns a connection to the POP3 server. If there was no connection yet, it will be created transparently. If the connection with the POP3 server was lost, it will be reconnected and the assures that internal state information (STAT and UIDL) is up-to-date in the object.

If the contact to the server was still present, or could be established, an IO::Socket::INET object is returned. Else, "undef" is returned and no further actions should be tried on the object.

Update the current status of folder on the remote POP3 server.

Server connection

Extends ``Server connection'' in Mail::Transport::Receive.
$obj->findBinary( $name, [@directories] )
Inherited, see ``Server connection'' in Mail::Transport
Inherited, see ``Server connection'' in Mail::Transport
Inherited, see ``Server connection'' in Mail::Transport
Represent this pop3 connection as URL.

Error handling

Extends ``Error handling'' in Mail::Transport::Receive.
Inherited, see ``Error handling'' in Mail::Reporter
Inherited, see ``Error handling'' in Mail::Reporter
$obj->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
Mail::Transport::POP3->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
Inherited, see ``Error handling'' in Mail::Reporter
Inherited, see ``Error handling'' in Mail::Reporter
$obj->log( [$level, [$strings]] )
Mail::Transport::POP3->log( [$level, [$strings]] )
Inherited, see ``Error handling'' in Mail::Reporter
Inherited, see ``Error handling'' in Mail::Reporter
Inherited, see ``Error handling'' in Mail::Reporter
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
Inherited, see ``Error handling'' in Mail::Reporter


Extends ``Cleanup'' in Mail::Transport::Receive.
Inherited, see ``Cleanup'' in Mail::Reporter


Error: Cannot connect to $host:$port for POP3: $!
Unsuccesful in connecting to the remote POP3 server.
Error: Cannot get the messages of pop3 via messages()
It is not possible to retrieve all messages on a remote POP3 folder at once: each shall be taken separately. The POP3 folder will hide this for you.
Error: Cannot re-connect reliably to server which doesn't support UIDL.
The connection to the remote POP3 was lost, and cannot be re-established because the server's protocol implementation lacks the necessary information.
Error: Cannot read POP3 from socket: $!
It is not possible to read the success status of the previously given POP3 command. Connection lost?
Error: Cannot write POP3 to socket: $@
It is not possible to send a protocol command to the POP3 server. Connection lost?
Error: Could not authenticate using '$some' method.
The authenication method to get access to the POP3 server did not result in a connection. Maybe you need a different authentication protocol, or your username with password are invalid.
Error: Could not authenticate using any login method.
No authentication method was explicitly prescribed, so both AUTH and APOP were tried. However, both failed. There are other authentication methods, which are not defined by the main POP3 RFC rfc1939. These protocols are not implemented yet. Please contribute your implementation.
Error: POP3 Could not do a STAT
For some weird reason, the server does not respond to the STAT call.
Error: POP3 requires a username and password.
No username and/or no password specified for this POP3 folder, although these are obligatory parts in the protocol.
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: Server at $host:$port does not seem to be talking POP3.
The remote server did not respond to an initial exchange of messages as is expected by the POP3 protocol. The server has probably a different service on the specified port.


Copyrights 2001-2015 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