Can anyone help me with this error! ! For SMTP sending a mail in mvc5

System.Net.Mail.SmtpException
  HResult=0x80131500
  Message=Failure sending mail.
  Source=studentlog
  StackTrace:
   at studentlog.Controllers.StudentController.Sendmail(MailMessage mail) in C:\Users\syashwan\source\repos\studentlog\Controllers\StudentController.cs:line 157
   at studentlog.Controllers.StudentController.BuildEmailtemplate(String SubjectText, String BodyText, String sendTo) in C:\Users\syashwan\source\repos\studentlog\Controllers\StudentController.cs:line 139
   at studentlog.Controllers.StudentController.BuildEmailtemplate(Int32 regId) in C:\Users\syashwan\source\repos\studentlog\Controllers\StudentController.cs:line 110
   at studentlog.Controllers.StudentController.Create(tblstapp tblstapp, AccountViewModel accountViewModel, Users usdata) in C:\Users\syashwan\source\repos\studentlog\Controllers\StudentController.cs:line 68
   at System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters)
   at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c.<BeginInvokeSynchronousActionMethod>b__9_0(IAsyncResult asyncResult, ActionInvocation innerInvokeState)
   at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.End()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass11_0.<InvokeActionMethodFilterAsynchronouslyRecursive>b__0()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2()

  This exception was originally thrown at this call stack:
    [External Code]

Inner Exception 1:
IOException: Unable to read data from the transport connection: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.

Inner Exception 2:
SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond

public ActionResult confirm(int regId)
       {
           ViewBag.regId = regId;
           return View();
       }
       public JsonResult RegisterConfirm(int regId)
       {
           tblstapp data = db.tblstapps.Where(x => x.Id == regId).FirstOrDefault();
           data.IsValid = true;
           db.SaveChanges();
           var msg = "Your email is verified";
           return Json(msg, JsonRequestBehavior.AllowGet);
       }
       public void BuildEmailtemplate(int regId)
       {
           string body = System.IO.File.ReadAllText(HostingEnvironment.MapPath("/EmailTemplate/") + "Text" + ".cshtml");
           var regInfo = db.tblstapps.Where(X => X.Id == regId).FirstOrDefault();
           var url = "https://localhost:44353/" + "Student/Confirm?regId=" + regId;
           body = body.Replace("@viewBag.ConfirmationLink", url);
           body = body.ToString();
           BuildEmailtemplate("Your account Created succefully", body, regInfo.Email);

       }

       public static void BuildEmailtemplate(string SubjectText,string BodyText,string sendTo)
       {
           string from, to, bcc, cc, subject, body;
           from = "Your email";
           to = sendTo.Trim();
           bcc = "";
           cc = "";
           subject = SubjectText;
           StringBuilder sb = new StringBuilder();
           sb.Append(BodyText);
           body = sb.ToString();
           MailMessage mail = new MailMessage();
           mail.From = new MailAddress(from);
           mail.To.Add(new MailAddress(to));
           if (!string.IsNullOrEmpty(bcc))
           {
               mail.Bcc.Add(new MailAddress(bcc));
                   }
           if (!string.IsNullOrEmpty(cc))
           {
               mail.Bcc.Add(new MailAddress(cc));
           }
           mail.Subject = subject;
           mail.Body = body;
           mail.IsBodyHtml = true;
           Sendmail(mail);

       }
       public static void Sendmail(MailMessage mail)
       {
           SmtpClient client = new SmtpClient();
           client.Host = "smtp.gamil.com";
           client.Port = 587;
           client.EnableSsl = true;
           client.UseDefaultCredentials = false;
           client.DeliveryMethod = SmtpDeliveryMethod.Network;
           client.Credentials = new System.Net.NetworkCredential("Your email", "Password");
           try
           {
               client.Send(mail);
           }
           catch (Exception ex)
           {
               throw ex;
           }
       }