C#: How to add read notifications

See more:

C#3.0

C#

Hi,

Here I am developing one desktop application using c# for sending mails. In that I want to add mail read notification. I have used the code below but it is not working. -- any help is greatly appreciated.

Mail is going, but i am not getting any read notification.

using System.Net.Mail;

MailMessage Msg = new MailMessage();
Msg.From =new System.Net.Mail.MailAddress("FromID");
Msg.To.Add("ToId");
Msg.Subject = "hai";
Msg.Body = "sss";
Msg.Headers.Add("Disposition-Notification-To", "ReturnID");
SmtpClient smtp = new SmtpClient("servername",port);

smtp.UseDefaultCredentials = false;
smtp.Credentials = new NetworkCredential("sendingID", "MyPwd","Domain");

smtp.Host = "Hostname";

smtp.Send(Msg);

Thanks
Sujith