protected function _addAddress($email, $name, $type) {

        $type = '_'.$type;

        $allowed = array(
            '_sender',
            '_from',
            '_to',
            '_cc',
            '_bcc',
            '_reply_to'
        );

        if (in_array($type, $allowed)) {
            if ($name != '') {
                $this->{$type}[$email] = $name;
            } else {
                $this->{$type}[] = $email;
            }
        }
    }