try
            {
                MailMessage mm = new MailMessage();
                MailAddress Fromma = new MailAddress("xxxx@qq.com");
                MailAddress Toma = new MailAddress("MMMMMMM@qq.com", null);
                mm.From = Fromma;
                //收件人
                mm.To.Add("MMMMMM@qq.com");
                //郵箱標題
                mm.Subject = "Hello Dear:";
                mm.IsBodyHtml = true;
                //郵件內容
                mm.Body = "你好Mr流星！";
                //內容的編碼格式
                mm.BodyEncoding = System.Text.Encoding.UTF8;
                //mm.ReplyTo = Toma;
                //mm.Sender =Fromma;
                //mm.IsBodyHtml = false;
                mm.DeliveryNotificationOptions = DeliveryNotificationOptions.OnSuccess;
                mm.CC.Add(Toma);
                SmtpClient sc = new SmtpClient();
                NetworkCredential nc = new NetworkCredential();
                nc.UserName = "XXXXX@qq.com";//你的郵箱地址
                nc.Password = "zzzzz";//你的郵箱密碼,這里的密碼是xxxxx@qq.com郵箱的密碼，特別說明下~
                   sc.UseDefaultCredentials = true;
                sc.DeliveryMethod = SmtpDeliveryMethod.Network;
                sc.Credentials = nc;
                //如果這里報mail from address must be same as authorization user這個錯誤，是你的QQ郵箱沒有開啟SMTP，
                //到你自己的郵箱設置一下就可以啦！在帳戶下面,如果是163郵箱的話，下面該成smtp.163.com
                sc.Host = "smtp.qq.com";
                sc.Send(mm);

            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }