public function send()
    {
        global $ilDB, $lng, $ilSetting;
        $is_message_enabled = $ilSetting->get("mail_notification_message");
        $res = $ilDB->queryF('SELECT mail.* FROM mail_options
						INNER JOIN mail ON mail.user_id = mail_options.user_id
						INNER JOIN mail_obj_data ON mail_obj_data.obj_id = mail.folder_id
						WHERE cronjob_notification = %s
						AND send_time >= %s
						AND m_status = %s', array('integer', 'timestamp', 'text'), array(1, date('Y-m-d H:i:s', time() - 60 * 60 * 24), 'unread'));
        $users = array();
        $user_id = 0;
        while ($row = $ilDB->fetchAssoc($res)) {
            if ($user_id == 0 || $row['user_id'] != $user_id) {
                $user_id = $row['user_id'];
            }
            $users[$user_id][] = $row;
        }
        foreach ($users as $user_id => $mail_data) {
            $this->initLanguage($user_id);
            $user_lang = $this->getLanguage() ? $this->getLanguage() : $lng;
            $this->initMail();
            $this->setRecipients($user_id);
            $this->setSubject($this->getLanguageText('mail_notification_subject'));
            $this->setBody(ilMail::getSalutation($user_id, $this->getLanguage()));
            $this->appendBody("\n\n");
            if (count($mail_data) == 1) {
                $this->appendBody(sprintf($user_lang->txt('mail_at_the_ilias_installation'), count($mail_data), ilUtil::_getHttpPath()));
            } else {
                $this->appendBody(sprintf($user_lang->txt('mails_at_the_ilias_installation'), count($mail_data), ilUtil::_getHttpPath()));
            }
            $this->appendBody("\n\n");
            $counter = 1;
            foreach ($mail_data as $mail) {
                $this->appendBody("----------------------------------------------------------------------------------------------");
                $this->appendBody("\n\n");
                $this->appendBody('#' . $counter . "\n\n");
                $this->appendBody($user_lang->txt('date') . ": " . $mail['send_time']);
                $this->appendBody("\n");
                if ($mail['sender_id'] == ANONYMOUS_USER_ID) {
                    $sender = ilMail::_getIliasMailerName();
                } else {
                    $sender = ilObjUser::_lookupLogin($mail['sender_id']);
                }
                $this->appendBody($user_lang->txt('sender') . ": " . $sender);
                $this->appendBody("\n");
                $this->appendBody($user_lang->txt('subject') . ": " . $mail['m_subject']);
                $this->appendBody("\n\n");
                if ($is_message_enabled == true) {
                    $this->appendBody($user_lang->txt('message') . ": " . $mail['m_message']);
                    $this->appendBody("\n\n");
                }
                ++$counter;
            }
            $this->appendBody("----------------------------------------------------------------------------------------------");
            $this->appendBody("\n\n");
            $this->appendBody($user_lang->txt('follow_link_to_read_mails') . " ");
            $this->appendBody("\n");
            $mailbox_link = ilUtil::_getHttpPath();
            $mailbox_link .= "/goto.php?target=mail&client_id=" . CLIENT_ID;
            $this->appendBody($mailbox_link);
            $this->appendBody("\n\n");
            $this->appendBody(ilMail::_getAutoGeneratedMessageString($this->getLanguage()));
            $this->appendBody(ilMail::_getInstallationSignature());
            $mmail = new ilMimeMail();
            $mmail->autoCheck(false);
            $mmail->From(ilMail::getIliasMailerAddress());
            $mmail->To(ilObjUser::_lookupEmail($user_id));
            $mmail->Subject($this->getSubject());
            $mmail->Body($this->getBody());
            $mmail->Send();
        }
    }