MailAddress to = new MailAddress(errorEmailTo);
        MailAddress from = new MailAddress(mailFrom);

        using (MailMessage mail = new MailMessage(from.Address, to.Address))
        {
            SmtpClient client = new SmtpClient();
            NetworkCredential credentials = new NetworkCredential(mailUser, mailPassword);
            try
            {
                client.Host = mailHost;
                client.Port = port;
                if (enableSSL == "Y")
                {
                    client.EnableSsl = true;
                }
                client.UseDefaultCredentials = false;
                client.Credentials = credentials;
                //client.DeliveryMethod = SmtpDeliveryMethod.Network;
                mail.Subject = "Test Message. Client ID: " + clientID;
                mail.Body = "Please find the message from BTC Client ID Title: "
                            + clientIDTitle
                            + " "
                            + msg;

                client.Send(mail);

                MessageBox.Show("Sent email to " + errorEmailTo + "n Enable SSL = " + enableSSL);
                button1.BackColor = Color.GreenYellow;
            }
            catch (Exception ex)
            {
                button1.BackColor = Color.Red;

                MessageBox.Show("ERROR. Cannot send email to " + errorEmailTo  + " Error Message: " + ex.Message
                    + "nEnable SSL = " + enableSSL
                    + "nExc. Type = " + ex.GetType().ToString()
                    + "nStack Trace = " + ex.StackTrace
                    + "n");

            }
        }





ERROR. Cannot send email to xxxx Error Message: Failure sending mail.
Enable SSL = Y
Exc. Type = System.Net.Mail.SmtpException
Stack Trace =    at System.Net.Mail.SmtpClient.Send(MailMessage message)

   at BTCClientUtilities.Form1.SendEmailTo(String errorEmailTo, String msg)