首先添加命名空间using System.Net.Mail;  /// <summary>        /// 发送邮件        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        protected void ForMail(string name, string mail)        {            try            {                //string email = txtemail.Text.Trim();                MailAddress MessageFrom = new MailAddress("【发件箱地址】"); //发件人邮箱地址                string MessageTo = mail; //收件人邮箱地址                string MessageSubject = bs.HtmlEncode(web_zt.Value.Trim()); //邮件主题                  string MessageBody = "" + content1.Value.Trim() + ""; //邮件内容 （一般是一个网址链接，生成随机数加验证id参数，点击去网站验证。）";                if (Send(MessageFrom, MessageTo, MessageSubject, MessageBody))                {                    //Response.Write("发送邮件成功");                }                else                {                    //Response.Write("发送邮件失败");                }            }            catch            {                //ClientScript.RegisterStartupScript(ClientScript.GetType(), "myscript", "<script>alert(‘客户信息删除失败‘)</script>");            }        }        /// <summary>        /// 发送电子邮件        /// </summary>        /// <param name="MessageFrom">发件人邮箱地址</param>        /// <param name="MessageTo">收件人邮箱地址</param>        /// <param name="MessageSubject">邮件主题</param>        /// <param name="MessageBody">邮件内容</param>        /// <returns></returns>        public bool Send(MailAddress MessageFrom, string MessageTo, string MessageSubject, string MessageBody)        {            MailMessage message = new MailMessage();            message.From = MessageFrom;            message.To.Add(MessageTo); //收件人邮箱地址可以是多个以实现群发            message.Subject = MessageSubject;            message.Body = MessageBody;            message.IsBodyHtml = true; //是否为html格式            message.Priority = MailPriority.Normal; //发送邮件的优先等级            SmtpClient sc = new SmtpClient();            sc.Host = "smtp.qq.com"; //指定发送邮件的服务器地址或IP            sc.Port = 25; //指定发送邮件端口            sc.Credentials = new System.Net.NetworkCredential("【发件箱地址】", "【发件箱密码】"); //指定登录服务器的用户名和密码(发件人的邮箱登陆密码)            try            {                sc.Send(message); //发送邮件            }            catch            {                return false;            }            return true;        }