app/bundles/EmailBundle/MonitoredEmail/Processor/ProcessorInterface.php

<?php

namespace Mautic\EmailBundle\MonitoredEmail\Processor;

use Mautic\EmailBundle\MonitoredEmail\Message;

interface ProcessorInterface
{
    /**
     * Process the message.
     *
     * @return bool|void
     */
    public function process(Message $message);
}