sendToSlack(cardView, discloser);
        sendToGoogleChat(cardView, discloser);
    }

    protected void sendToSlack(final CardView cardView, final SMailPostingDiscloser discloser) {
        // https://api.slack.com/messaging/webhooks#posting_with_webhooks
        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        final String slackWebhookUrls = fessConfig.getSlackWebhookUrls();

 - [S3](https://github.com/codelibs/fess-ds-s3)
 - [Salesforce](https://github.com/codelibs/fess-ds-salesforce)
 - [SharePoint](https://github.com/codelibs/fess-ds-sharepoint)
 - [Slack](https://github.com/codelibs/fess-ds-slack)

## Theme

 - [Simple](https://github.com/codelibs/fess-theme-simple)
 - [Classic](https://github.com/codelibs/fess-theme-classic)

## Ingest

    public static final String SEARCH_FILE_PROXY_PROPERTY = "search.file.proxy";

    public static final String NOTIFICATION_TO_PROPERTY = "notification.to";

    public static final String SLACK_WEBHOOK_URLS_PROPERTY = "slack.webhook.urls";

    public static final String GOOGLE_CHAT_WEBHOOK_URLS_PROPERTY = "google.chat.webhook.urls";

    }

    default void setSlackWebhookUrls(final String value) {
        setSystemProperty(Constants.SLACK_WEBHOOK_URLS_PROPERTY, value);
    }

    default String getSlackWebhookUrls() {
        return getSystemProperty(Constants.SLACK_WEBHOOK_URLS_PROPERTY, StringUtil.EMPTY);
    }

    default void setGoogleChatWebhookUrls(final String value) {