static HtmlEmail setAuthentication(HtmlEmail email) {
   if (!(CommandsEX.getConf().getString("Email.Username").isEmpty()
       && CommandsEX.getConf().getString("Email.Password").isEmpty())) {
     email.setAuthentication(
         CommandsEX.getConf().getString("Email.Username"),
         CommandsEX.getConf().getString("Email.Password"));
   }
   return email;
 }