src/IronMQ.php
public function deleteMessages($queue_name, $messages)
    {
        $req = array(
            "ids" => array(),
        );
        foreach ($messages as $message) {
            if (is_string($message)) {
                array_push($req['ids'], $message);
            } else if (is_object($message)) {
                array_push($req['ids'], array('id' => $message->id, 'reservation_id' => $message->reservation_id));
            } else if (is_array($message)) {
                array_push($req['ids'], array('id' => $message['id'], 'reservation_id' => $message['reservation_id']));
            }
        }
        $this->setJsonHeaders();
        $queue = rawurlencode($queue_name);
        $url = "projects/{$this->project_id}/queues/$queue/messages";
        $result = $this->apiCall(self::DELETE, $url, $req);
        return self::json_decode($result);
    }
public function deleteMessages($queue_name, $messages)
    {
        $req = array(
            "ids" => array(),
        );
        foreach ($messages as $message) {
            if (is_string($message)) {
                array_push($req['ids'], $message);
            } else if (is_object($message)) {
                array_push($req['ids'], array('id' => $message->id, 'reservation_id' => $message->reservation_id));
            } else if (is_array($message)) {
                array_push($req['ids'], array('id' => $message['id'], 'reservation_id' => $message['reservation_id']));
            }
        }
        $this->setJsonHeaders();
        $queue = rawurlencode($queue_name);
        $url = "projects/{$this->project_id}/queues/$queue/messages";
        $result = $this->apiCall(self::DELETE, $url, $req);
        return self::json_decode($result);
    }
Delete Messages from a Queue
This call will delete the messages. Be sure you call this after you’re done with a message,
or it will be placed back on the queue.

@param $queue_name
@param $messages
@return mixed