*
     * @param form the mail form containing notification settings
     * @return HTML response after sending test mail
     */
    @Execute
    @Secured({ ROLE })
    public HtmlResponse sendmail(final MailForm form) {
        validate(form, messages -> {}, () -> asHtml(path_AdminGeneral_AdminGeneralJsp));

        final String[] toAddresses = form.notificationTo.split(",");