Problem about sending email with MVC

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MVC

In localhost it works fine,
In live it provide Error:

Error msg:
Request for the permission of type 'System.Net.Mail.SmtpPermission, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed


help me my code is:

public ActionResult Email(RegInfo registration)
{
try
{
var from = System.Configuration.ConfigurationManager.AppSettings["UserName"];
var smtpHost = System.Configuration.ConfigurationManager.AppSettings["Host"];
var mailPwd = System.Configuration.ConfigurationManager.AppSettings["MailPwd"];
var smtpPort = Convert.ToInt32(System.Configuration.ConfigurationManager.AppSettings["Port"]);
var callBackUrl = System.Configuration.ConfigurationManager.AppSettings["CallBackUrl"] + registration.ROLEBYID;
var msg = new MailMessage(from, registration.EMAIL) { Subject = "Verify Your Account" };
var Body = string.Format("Hi {0}
Your Account Registerd.
Your Id is :{1}
Please confirm your account by clicking <a href=\"{2}\">here", registration.NAME, registration.ROLEBYID, callBackUrl);
msg.Body = Body;
msg.IsBodyHtml = true;
var smtp = new SmtpClient()
{
Host = smtpHost,
Port = smtpPort,
DeliveryMethod = SmtpDeliveryMethod.Network,
UseDefaultCredentials = false,
Credentials = new System.Net.NetworkCredential(from, mailPwd), EnableSsl = true
};
smtp.Send(msg);
return RedirectToAction("Create");



}
catch (Exception ex)
{
TempData["error"] = ex.Message;
return RedirectToAction("Create");
}
}

What I have tried:

Changed ssl to false , but not working