try
 {
      //create the object for the class SmtpClient
      SmtpClient smtpMailObj = new SmtpClient();
      //supply your mail server
      smtpMailObj.Host = "mailservername";
      smtpMailObj.Send(txtFrom.Text,txtTo.Text,txtSubject.Text,txtComment.Text);
      Response.Write("Your Message has been sent Successfully");
 }
 catch(Exception ee)
 {
   Response.Write("Delivery Failed");
 }