c#发qq邮箱，QQ邮箱当中开启“POP3/SMTP服务”获取授权码

            //发件人地址
            MailAddress from = new MailAddress("824478152@qq.com");
            MailMessage message = new MailMessage();
            message.Body = "this is a test";
            message.IsBodyHtml = true;
            message.BodyEncoding = System.Text.Encoding.UTF8;
            //收件人地址
            message.To.Add("824478152@qq.com");
            message.Subject = "hello !";
            message.SubjectEncoding = System.Text.Encoding.UTF8;
            message.From = from;
            SmtpClient client = new SmtpClient();
            client.EnableSsl = true;
            client.Host = "smtp.qq.com";
            client.Port = 587;
            //邮箱账户和密码
            client.Credentials = new System.Net.NetworkCredential("824478152@qq.com", "授权码");
            try
            {
                client.Send(message);
            }
            catch (Exception ex)
            {
                string mssage = ex.ToString();
            }

        /// 

        /// 同步发送邮件
        /// 
        /// 收件人邮箱地址
        /// 主题
        /// 内容
        /// 编码
        /// 是否Html
        /// 是否SSL加密连接
        /// 是否成功
        public static bool Send(string to, string subject, string body, string encoding = "UTF-8", bool isBodyHtml = true, bool enableSsl = false)
        {
            try
            {
                MailMessage message = new MailMessage();
                // 接收人邮箱地址
                message.To.Add(new MailAddress(to));
                message.From = new MailAddress(MailUserName, MailName);
                message.BodyEncoding = Encoding.GetEncoding(encoding);
                message.Body = body;
                //GB2312
                message.SubjectEncoding = Encoding.GetEncoding(encoding);
                message.Subject = subject;
                message.IsBodyHtml = isBodyHtml;

                SmtpClient smtpclient = new SmtpClient(MailServer, 587);
                smtpclient.Credentials = new System.Net.NetworkCredential(MailUserName, MailPassword);
                //SSL连接
                smtpclient.EnableSsl = enableSsl;
                smtpclient.Send(message);
                return true;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
                return false;
            }
        }