asp.net - The server response was: 4.3.2 Service not available, closing transmission channel

Question

I am getting this error while sending email from my application. Can anyone suggest any solution.

Service not available, closing transmission channel. The server response was: 4.3.2 Service not available, closing transmission channel

Below is code.

string adminID = "AAA@tu.edu";
MailMessage msg = new MailMessage();
msg.From = new MailAddress(adminID);
msg.To.Add("BBB@ttu.edu");
msg.Subject = "Sample Email";
msg.Body = "Hello ";
SmtpClient SmtpMail = new SmtpClient();
SmtpMail.Host = "basic.smtp.ttu.edu";
SmtpMail.Port = 25;
SmtpMail.Send(msg);

Answer 1

Got the solution for the issue. The Server was rejecting the request because this application didn't have write rights on that server. The code was perfectly fine, just it was permissions problem. Hope this helps someone!