public ActionResult MailList(int skip = 0, int take = 50, SpecialFolder specialFolder = SpecialFolder.All)
 {
     try
     {
         MailRepository mailRepository = Session["MailRepository"] as MailRepository;
         MailRepositoryResult <EnvelopeEmail> response = mailRepository.SearchAdvanced(skip, take, specialFolder);
         return(View(response.Obj));
     }
     catch (Exception)
     {
         return(View("null"));
     }
 }