Smtp 我能'；t在Godaddy主机C上发送带有SSL证书的电子邮件#

我正在使用godaddy windows主机。 我尝试发送带有SSL证书的电子邮件，因为我确实需要SSL来防止我的电子邮件被标记为垃圾邮件

这就是错误： 连接尝试失败，因为连接方在一段时间后没有正确响应，或者建立的连接失败，因为连接的主机未能响应198.71.232.1:465

这里是我的代码，但它不起作用：

using (MailMessage newMail = new MailMessage(from, to))
    {
        newMail.Subject = "royaltaxies";
        newMail.Body = body;
        newMail.IsBodyHtml = true;
        SmtpClient smtp = new SmtpClient();
        smtp.Host = "relay-hosting.secureserver.net";
        smtp.EnableSsl = true;
        //add following code before smtpClient.Send()
        ServicePointManager.ServerCertificateValidationCallback = delegate (object s, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors) { return true; };
        NetworkCredential NetworkCred = new NetworkCredential(from, "******");
        smtp.UseDefaultCredentials = false;
        smtp.Credentials = NetworkCred;
        smtp.Port = 587;
        smtp.Send(newMail);
    }
}