Mailster support

function pm_extra_mailster_endpoints($endpoints) {
    if(function_exists('mailster_option')) {
        $slugs = implode('|', (array) mailster_option('slugs', array('confirm', 'subscribe', 'unsubscribe', 'profile')));
        $endpoints .= "|{$slugs}";
    }

    return $endpoints;
}
add_filter('permalink_manager_endpoints', 'pm_extra_mailster_endpoints');

function pm_detect_mailster_urls() {
    global $pm_query, $wp_query;

    if(!function_exists('mailster_option') || empty($pm_query['endpoint'])) {
        return;
    }

    // Get list of Mailster endpoints
    $slugs = (array) mailster_option('slugs', array('confirm', 'subscribe', 'unsubscribe', 'profile'));

    if(in_array($pm_query['endpoint'], $slugs)) {
        $wp_query->query_vars['_mailster_page'] = $pm_query['endpoint'];

        // Detect hash & extra parameter
        preg_match('/([a-f0-9]{32})?\/?([a-z0-9\/]*)/', $pm_query['endpoint_value'], $parts);
        $wp_query->query_vars['_mailster_hash'] = $parts[1];

        if(!empty($parts[2])) {
            $wp_query->query_vars['_mailster_extra'] = $parts[2];
        }
    }
}
add_action('wp', 'pm_detect_mailster_urls', 99);