邮件发送验证码

 if (!string.IsNullOrEmpty(this.txtMail.Text))
            {
                try
                {
                    //声明一个Mail对象
                    MailMessage mymail = new MailMessage();
                    //发件人地址
                    //如是自己，在此输入自己的邮箱
                    mymail.From = new MailAddress(ConfigurationManager.AppSettings["MEAILADDRESS"].ToString());
                    //收件人地址
                    mymail.To.Add(new MailAddress(this.txtMail.Text));
                    //邮件主题
                    mymail.Subject = "用户绑定验证码（请勿回复此邮件）";
                    //邮件标题编码
                    mymail.SubjectEncoding = System.Text.Encoding.UTF8;
                    //发送邮件的内容
                    string checkCode = new Random().Next(100000, 1000000).ToString();
                    if (Session["CheckCode"] == null)
                    {
                        Session["CheckCode"] = checkCode;
                    }
                    mymail.Body = "亲爱的用户

您好，您本次验证码为：" + checkCode + ",该验证码有效期为" + ConfigurationManager.AppSettings["TIMEOUT"].ToString() + "分钟，切勿告诉他人。";
                    //邮件内容编码
                    mymail.BodyEncoding = System.Text.Encoding.UTF8;
                    //是否是HTML邮件
                    mymail.IsBodyHtml = true;
                    //邮件优先级
                    mymail.Priority = MailPriority.High;
                    //创建一个邮件服务器类
                    SmtpClient myclient = new SmtpClient();
                    myclient.Host = "smtp.163.com";
                    //SMTP服务端口
                    myclient.Port = 25;
                    //验证登录
                    myclient.Credentials = new NetworkCredential(ConfigurationManager.AppSettings["MEAILADDRESS"].ToString(), ConfigurationManager.AppSettings["MEAILPASSWORD"].ToString());//"@"输入有效的邮件名, "*"输入有效的密码
                    myclient.Send(mymail);
                    this.lblSend.Text = "验证码已发送到您的邮箱，请登录邮箱查看";
                }
                catch (Exception)
                {
                    this.lblSend.Text = "验证码获取失败，请重新获取";
                }

                ClientScript.RegisterStartupScript(ClientScript.GetType(), "myscript", "");
            }
            else
            {
                this.lblMsg.Text = "请输入邮箱！";
            }