public ActionResult SendMails()
        {
            AccountVM acc = new AccountVM();
            BorrowingVM bor = new BorrowingVM();
            BookVM book = new BookVM();

            var emails = from b in book.Get_list()
                         from o in bor.Get_list()
                         from a in acc.Get_list()
                         where o.BookID==b.BookID && a.AccountID==o.ReaderID && o.Returned==false && o.Return_date < DateTime.Now
                         select new
                         {
                             a.Email,
                             b.Title
                         };

            GMailer.GmailUsername = "panmail1212p@gmail.com";
            GMailer.GmailPassword = "zaq1@wsx";
            GMailer mailer = new GMailer();
            foreach (var e in emails)
            {
                mailer.ToEmail = e.Email;
                mailer.Subject = "BIBLIOTEKA - Zwrot książki";
                mailer.Body = "Prosimy o zwrot książki '" + e.Title + "' !";
                mailer.IsHtml = true;
                mailer.Send();
            }
            ViewBag.Mails1 = "Wysłano próśb " + emails.Count();

            var emails1 = from b in book.Get_list()
                         from o in bor.Get_list()
                         from a in acc.Get_list()
                         where o.BookID == b.BookID && a.AccountID == o.ReaderID && o.Returned == false  && o.Return_date.Date == DateTime.Now.Date.AddDays(1)
                          select new
                         {
                             a.Email,
                             b.Title
                         };

            foreach (var e in emails1)
            {
                mailer.ToEmail = e.Email;
                mailer.Subject = "BIBLIOTEKA - Przypomnienie o zwrocie książki!";
                mailer.Body = "Został jeden dzień do zwrotu książki '" + e.Title + "' ! Po upływie czasu kara zastanie naliczona!";
                mailer.IsHtml = true;
                mailer.Send();
            }

            ViewBag.Mails2 = "Wysłano przypomnień " + emails1.Count();
            return View("Admin");
        }