} else {
                    toAddresses = StringUtil.EMPTY_STRINGS;
                }
                final NotificationHelper notificationHelper = ComponentUtil.getNotificationHelper();
                SMailCallbackContext.setPreparedMessageHookOnThread(notificationHelper::send);
                CrawlerPostcard.droppedInto(postbox, postcard -> {

    private static final String SCRIPT_ENGINE_FACTORY = "scriptEngineFactory";

    private static final String INGEST_FACTORY = "ingestFactory";

    private static final String NOTIFICATION_HELPER = "notificationHelper";

    private static final String SEARCH_HELPER = "searchHelper";

    private static final String THEME_HELPER = "themeHelper";

    private static final String PLUGIN_HELPER = "pluginHelper";