How to send mail from web application using asp.net and c#?

MailMessage mail = new MailMessage();
SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com");

mail.From = new MailAddress("your_email_address@gmail.com");
mail.To.Add("2128675309@cingularme.com");
mail.Subject = "Test Mail";
mail.Body = "This is for testing SMTP mail from GMAIL";
SmtpServer.Port = 587;
SmtpServer.Credentials = new System.Net.NetworkCredential("username", "password");
SmtpServer.EnableSsl = true;
SmtpServer.Send(mail);
MessageBox.Show("mail Send");