What about this?

use strict;
use Mail::POP3Client;
my $pop3 = new Mail::POP3Client();  # default is localhost
$pop3->User( "somebody" );
$pop3->Pass( "doublesecret" );
$pop3->Connect() || die "failed: $pop3->Message()\n";
$pop3->Close();
[download]

or this:

use strict;
use Mail::POP3Client;
my $pop3 = new Mail::POP3Client( HOST  => 'biztos.com' );
$pop3->User( "somebody" );
$pop3->Pass( "doublesecret" );
$pop3->Connect() || die "failed: $pop3->Message()\n";
$pop3->Close();
[download]

Update: I seem to recall having issues with the Connect method. Another thing you might try is:

use strict;
use Mail::POP3Client;
my $pop3 = new Mail::POP3Client();  # with & without the host
$pop3->User( "somebody" );
$pop3->Pass( "doublesecret" );
$pop3->Connect();
if ($pop3->Alive()) {
  # connection established
} else {
  # no connection
}
$pop3->Close();
[download]

2nd Update: The first two fail for me but the third works. I think that Mail::POP3Client has a bug in the Connect method now.

3rd Update: I downloaded the latest version of Mail::POP3Client from CPAN (AS had a very old version). Now all three work for me.