Unable To Read Data From The Transport Connection: Net_io_connectionclosed?

I'm getting this error when I'm send email from my page,

Unable to read data from the transport connection: net_io_connectionclosed

Here my code:

MailMessage msgMail = new MailMessage();
msgMail.From = new MailAddress("info@mydomain.com");
msgMail.To.Add(new MailAddress("emaill@otherdomain.com"));
msgMail.Subject = "Message from web";
msgMail.IsBodyHtml = true;
msgMail.Body = "Test message";
SmtpClient Client = new SmtpClient();
Client.Port = 587;
Client.Host = "smtp server name";
Client.ServicePoint.MaxIdleTime = 1;
Client.Send(msgMail);
msgMail.Dispose();