public void SendMail(string from, string to, List<string> cc, string subject, string body)
        {
            MailMessage message = new MailMessage();
            message.From = new MailAddress("webmaster@xxx");
            message.To.Add(to);
            if (cc.Count > 0)
            {
                foreach (string item in cc)
                {
                    message.CC.Add(item);
                }
            }
            message.Subject = subject;
            message.Body = body;
            message.IsBodyHtml = true;
            SmtpClient client = new SmtpClient();
            client.Send(message);
        }