雅虎smtp发送电子邮件时出错

我通过这篇文章配置了我的outlook 2010，以便从yahoo.com发送和接收电子邮件，它运行良好，没有任何问题。

我开发了一个小应用程序来通过我的应用程序发送电子邮件，但它给了我错误：

"unable to read data from the transport connection:an exist connection was 
 forcibly closed by the remote host."

我的代码：

  try
        {
            SmtpClient smtp = new SmtpClient("smtp.mail.yahoo.com", 465);
            smtp.UseDefaultCredentials = true;
            smtp.EnableSsl = true;
            smtp.Credentials = new System.Net.NetworkCredential("myid", "mypass");
            smtp.DeliveryMethod = SmtpDeliveryMethod.Network;
            MailMessage mailMessage = new MailMessage();
            mailMessage.From = new System.Net.Mail.MailAddress("myid@yahoo.com", "blabla");
            mailMessage.To.Add(new System.Net.Mail.MailAddress("xxx@live.com", "xxx@live.com"));
            mailMessage.Subject = "test";
            mailMessage.Body = "test";
            mailMessage.IsBodyHtml = false;
            mailMessage.SubjectEncoding = System.Text.Encoding.UTF8;
            mailMessage.BodyEncoding = System.Text.Encoding.UTF8;
            mailMessage.Priority = MailPriority.High;

            smtp.Send(mailMessage);
            Console.WriteLine("hooooooooooraaaaaaaaaaaaaaa");
            Console.ReadKey();
        }
        catch (Exception err)
        {
            Console.WriteLine(err.InnerException.Message);
            Console.ReadKey();
            return;
        }