private void btn_send_Click(object sender, EventArgs e)

        {

            var emailAcount = ConfigurationManager.AppSettings["EmailAcount"];

            var emailPassword = ConfigurationManager.AppSettings["EmailPassword"];

            var reciver = txt_Reciver.Text;

            var content = rtxt_Content.Text;

            MailMessage message = new MailMessage();

            //设置发件人,发件人需要与设置的邮件发送服务器的邮箱一致

            MailAddress fromAddr = new MailAddress("qwe123@qq.com");

            message.From = fromAddr;

            //设置收件人,可添加多个,添加方法与下面的一样

            message.To.Add(reciver);

            //设置抄送人

            message.CC.Add("qwe123@163.com");

            //设置邮件标题

            message.Subject = "Test";

            //设置邮件内容

            message.Body = content;

            //设置邮件发送服务器,服务器根据你使用的邮箱而不同,可以到相应的 邮箱管理后台查看,下面是QQ的

            SmtpClient client = new SmtpClient("smtp.qq.com", );

            //设置发送人的邮箱账号和密码

            client.Credentials = new NetworkCredential(emailAcount,emailPassword);

            //启用ssl,也就是安全发送

            client.EnableSsl = true;

            //发送邮件

            client.Send(message);

        }