Mandar mail con c# .net

using System.Net.Mail; using System.Net; 

public void sendEmail(string body)     {         string email = "admin@testdeoposiciones.com";         if (String.IsNullOrEmpty(email))             return;         try         {             MailMessage mail = new MailMessage();             mail.To.Add(email);             mail.To.Add("mailb@gmail.com");             mail.From = new MailAddress("mail@mail.com");             mail.Subject = "sub";              mail.Body = body;              mail.IsBodyHtml = true;             SmtpClient smtp = new SmtpClient();                          smtp.Host = "smtp.gmail.com"; //Or Your SMTP Server Address             smtp.Credentials = new NetworkCredential                  ("mail@mail.com", "contraseñadetumail"); // ***use valid credentials***             smtp.Port = 587;              //Or your Smtp Email ID and Password             smtp.EnableSsl = true;             smtp.Send(mail);         }         catch (Exception ex)         {             lblexcpecion.Text=("Exception in sendEmail:" + ex.Message); // en mi caso he creado un asplabel que se llama excepción, esto lo puedes quitar o crear algo para mostrar.         }     }