Email sending in C# gmail

using (MailMessage mm = new MailMessage("from@gmail.com", "to@gmail.com"))

            {

                mm.Subject = "Subject Text";

                mm.Body = "Body Text";

                mm.IsBodyHtml = false;

                SmtpClient smtp = new SmtpClient();

                smtp.Host = "smtp.gmail.com";

                smtp.EnableSsl = true;

                NetworkCredential NetworkCred = new NetworkCredential("from@gmail.com", "pwm");

                ServicePointManager.ServerCertificateValidationCallback =

                delegate(object s, X509Certificate certificate,

                         X509Chain chain, SslPolicyErrors sslPolicyErrors)

                { return true; };

                smtp.UseDefaultCredentials = false;

                smtp.Credentials = NetworkCred;

                smtp.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;

                smtp.Port = 587;

                smtp.Send(mm);

                //ClientScript.RegisterStartupScript(GetType(), "alert", "alert('Email sent.');", true);

            }