/// <summary>        /// 发送邮件        /// </summary>        /// <param name="title">邮箱内容</param>        /// <param name="Email">邮箱地址</param>        /// <param name="value">收件人姓名</param>        /// <returns></returns>        public string Small(string value,string Email,string title)        {            MailMessage mail;            SmtpClient client;            string EmailTitle = "877600684@qq.com";            mail = new MailMessage(EmailTitle,Email);            mail.Body = value;//内容            mail.Subject = title;//标题            mail.IsBodyHtml = true;            mail.SubjectEncoding = System.Text.Encoding.Default;            mail.BodyEncoding = System.Text.Encoding.Default;            //mail.Headers.Add("X-Priority", "3");            //mail.Headers.Add("X-MSMail-Priority", "Normal");            //mail.Headers.Add("X-Mailer", "Microsoft Outlook Express 6.00.2900.2869");            //mail.Headers.Add("X-MimeOLE", "Produced By Microsoft MimeOLE V6.00.2900.2869");            client = new SmtpClient("smtp.qq.com");            client.Credentials = new System.Net.NetworkCredential("用户名", "密码");         //   client.Host = "smtp.qq.com";            //System.Net.NetworkCredential crea = new System.Net.NetworkCredential();            //crea.UserName = "用户名";            //crea.Password = "密码";              System.IO.StreamWriter writer = new System.IO.StreamWriter("D:\\log.txt", true);            try {                client.Send(mail);                //发送成功                writer.WriteLine("邮件发送成功");                writer.Close();                return "0";                            }            catch (Exception e)            {                writer.WriteLine("邮件发送失败,错误信息:"+e.ToString());                writer.Close();                return "1";            }        }