//Email  實體類
 public class MyEmail
    {
        /// <summary>
        /// 傳送方傳送方伺服器地址
        /// </summary>
        public string strHost { get; set; }

        /// <summary>
        /// 傳送方帳號
        /// </summary>
        public string strAccount { get; set; }

        /// <summary>
        ///
 
 傳送方密碼
        /// </summary>
        public string strPwd { get; set; }

        /// <summary>
        /// 傳送方郵件地址
        /// </summary>
        public string strFrom { get; set; }

        /// <summary>
        /// 接收方郵件地址
        /// </summary>
        public string to { get; set; }

        ///
 
 <summary>
        /// 郵件標題
        /// </summary>
        public string title { get; set; }

        /// <summary>
        /// 郵件正文內容
        /// </summary>
        public string content { get; set; }

        /// <summary>
        /// 附件
        /// </summary>
        public string sfile { get
 
; set; }

    }

實現方法：

//傳送Email公共方法
 public class SendEmailHelp
    {

        /// <summary>
        /// 傳送郵件
        /// </summary>
        /// <param name="strHost">傳送方傳送方伺服器地址</param>
        /// <param name="strAccount">傳送方帳號</param>
        /// <param name="strPwd">傳送方密碼</param>
        ///  <param name="strFrom">傳送方郵件地址</param>
        /// <param name="to">接收方郵件地址</param>
        /// <param name="title">郵件標題</param>
        /// <param name="content">郵件正文內容</param>
        /// <param name="sfile">郵件附件</param>
        /// <returns></returns>
        public bool sendMail(MyEmail e)//string strHost, string strAccount, string strPwd, string strFrom, string to, string title, string content
        {
            SmtpClient smtpClient = new SmtpClient();
            if (string.IsNullOrEmpty(e.strHost))
            {
                e.strHost = "smtp.sina.cn";//新浪測試
            }
            if (string.IsNullOrEmpty(e.strAccount))
            {
                e.strAccount = "xxx";
            }
            if (string.IsNullOrEmpty(e.strPwd))
            {
                e.strPwd = "xxx";
            }
            if (string.IsNullOrEmpty(e.strFrom))
            {
                e.strFrom = "xxx";
            }
            smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;//指定電子郵件傳送方式
            smtpClient.Host = e.strHost; ;//指定SMTP伺服器
            smtpClient.Credentials = new System.Net.NetworkCredential(e.strAccount, e.strPwd);//使用者名稱和密碼

            MailMessage mailMessage = new MailMessage(e.strFrom, e.to);
            mailMessage.Subject = e.title;//主題
            mailMessage.Body = e.content;//內容
            mailMessage.BodyEncoding = System.Text.Encoding.UTF8;//正文編碼
            mailMessage.IsBodyHtml = true;//設定為HTML格式
            mailMessage.Priority = MailPriority.High;//優先順序
            //// 新增附件
            if (e.sfile != "")
            {
                mailMessage.Attachments.Add(new Attachment(e.sfile));
            }
            try
            {
                smtpClient.Send(mailMessage);
                mailMessage.Dispose();//釋放資源
                return true;
            }
            catch
            {
                return false;
            }
        }
    }