string userName = dt.Rows[0]["Email"].ToString();
string passWord = dt.Rows[0]["Pw"].ToString();
string smtpUrl = dt.Rows[0]["SMTPUrl"].ToString();
SmtpClient smtpClient = new SmtpClient(smtpUrl, 587);
smtpClient.EnableSsl = false;
smtpClient.Timeout = 10000;
smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;
smtpClient.UseDefaultCredentials = false;
smtpClient.Credentials = new NetworkCredential(userName, passWord);
MailMessage mail = new MailMessage(txtEmailFrom.Text.Trim(), txtSupplierEmail.Text, "From Contact: " + txtFullName.Text.Trim() + " Subject:" + txtSubject.Text.Trim(), txtMessage.Text.ToString());
mail.BodyEncoding = UTF8Encoding.UTF8;
mail.DeliveryNotificationOptions = DeliveryNotificationOptions.OnFailure;
smtpClient.Send(mail);