public JsonResult MailMultiAddFlags(List <string> uniqueId, MessageFlags messageFlags)
 {
     try
     {
         MailRepository mailRepository = Session["MailRepository"] as MailRepository;
         return(Json(mailRepository.MultiAddFlagsAdvanced(uniqueId, messageFlags), JsonRequestBehavior.AllowGet));
     }
     catch (Exception ex)
     {
         return(Json(false, JsonRequestBehavior.AllowGet));
     }
 }