C# SMTP Gmail เขียนส่ง email แล้ว error "Service not available, closing transmission channel."

	System.Net.Mail.MailMessage myMail = new System.Net.Mail.MailMessage();
	System.Net.NetworkCredential Cred = new System.Net.NetworkCredential("[email protected]", "password");

	myMail.To.Add("[email protected]");
	myMail.Subject = "Test send mail message";

	myMail.From = new System.Net.Mail.MailAddress("[email protected]");
	myMail.IsBodyHtml = true;
	myMail.Body = "Hi Sawatdee.<br><br>Sabye dee mai.";

	System.Net.Mail.SmtpClient SmtpMail = new System.Net.Mail.SmtpClient("smtp.gmail.com");
	SmtpMail.UseDefaultCredentials = false;
	SmtpMail.EnableSsl = true;
	SmtpMail.Credentials = Cred;
	SmtpMail.Port = 465;
	SmtpMail.Send(myMail);

	myMail = null;