function cron_hook()

function cron_hook() {
            global $wpdb, $Db, $Email, $History, $Subscriber, $SubscribersList, $Queue;
            $emailssent = 0;

            //update scheduling
            $this -> scheduling();
            $this -> autoresponders_hook();

            //ensure that scheduling has been turned on
            if ($this -> get_option('scheduling') == "Y") {
                $emailsperinterval = $this -> get_option('emailsperinterval');

                $emailsquery = "SELECT * FROM " . $wpdb -> prefix . $Queue -> table . " WHERE `senddate` < '" . date("Y-m-d H:i:s", time()) . "' LIMIT " . $emailsperinterval . "";

                //retrieve all the queue emails for this execution
                if ($emails = $wpdb -> get_results($emailsquery)) {
                //if ($emails = $Queue -> find_all(false, false, false, $emailsperinterval)) {
                    //send an email notification to the administrator if specified
                    if ($this -> get_option('schedulenotify') == "Y" && $this -> get_option('scheduling') == "Y") {
                        $subscriber_id = $Subscriber -> admin_subscriber_id($_POST['mailinglists']);
                        $subscriber = $Subscriber -> get($subscriber_id, false);
                        $subject = $this -> et_subject('schedule', $subscriber);
                        $fullbody = $this -> et_message('schedule', $subscriber);
                        $message = $this -> render_email(false, array('subscriber' => $subscriber, 'mailinglist' => $mailinglist), false, $this -> htmltf($subscriber -> format), true, $this -> default_theme_id(), false, $fullbody);
                        $this -> execute_mail($subscriber, $subject, $message, false, false, false, false);
                    }

                    $subscriber = false;
                    $subscriberids = array();
                    $subscriberemails = array();
                    $emailssent = 0;

                    foreach ($emails as $email) {
                        $this -> remove_server_limits();

                        $historyquery = "SELECT `post_id` FROM `" . $wpdb -> prefix . $History -> table . "` WHERE `id` = '" . $email -> history_id . "'";
                        if ($history_post_id = $wpdb -> get_var($historyquery)) {
                            if ($getpost = get_post($history_post_id)) {
                                global $post;
                                $post = $getpost;
                            }
                        }

                        if ($subscriber = $Subscriber -> get($email -> subscriber_id, false)) {
                            $subscriber -> mailinglist_id = $email -> mailinglist_id;
                            $subscriber -> mailinglists = $email -> mailinglists;
                            $eunique = md5($subscriber -> id . $subscriber -> mailinglist_id . $email -> history_id . date("YmdH", time()));

                            $checkemailquery = "SELECT `id` FROM `" . $wpdb -> prefix . $Email -> table . "` WHERE `eunique` = '" . $eunique . "' AND `history_id` = '" . $email -> history_id . "'";
                            if (!$wpdb -> get_var($checkemailquery)) {
                                if (empty($subscriberids) || (!empty($subscriberids) && !in_array($subscriber -> id, $subscriberids))) {
                                    $subscriberids[] = $subscriber -> id;

                                    if ((empty($subscriberemails[$email -> history_id])) || (!empty($subscriberemails[$email -> history_id]) && !in_array($subscriber -> email, $subscriberemails[$email -> history_id]))) {
                                        $subscriberemails[$email -> history_id][] = $subscriber -> email;

                                        $Db -> model = $Email -> model;
                                        $message = $this -> render_email('send', array('message' => $email -> message, 'subject' => $email -> subject, 'subscriber' => $subscriber, 'history_id' => $email -> history_id, 'post_id' => $email -> post_id, 'eunique' => $eunique), false, $this -> htmltf($subscriber -> format), true, $email -> theme_id);

                                        if ($this -> execute_mail($subscriber, $email -> subject, $message, $email -> attachments, $email -> history_id, $eunique)) {
                                            $Queue -> delete($email -> id);
                                            $emailssent++;
                                        }
                                    }
                                }
                            }
                        } else {
                            $Queue -> delete($email -> id);
                        }

                        $subscriber = array();
                    }
                }
            }

            //update the "lastcron" setting
            $this -> update_option('lastcron', time());
            echo $emailssent . " " . __('emails have been sent out', $this -> plugin_name);
        }