C# 發送 Email

 //Email function
        private  string Send_Mail(string s_from, string s_to, string m_title, string m_body, string m_file)
        {
            // 's_from 發件箱地址
            //'pwd 發件箱密碼
            //' s_to 收件箱地主之誼
            //'m_title 郵件主題
            //'m_body 郵件內容
            //'m_file 附件

            // '构建MailMessage对象
            System.Net.Mail.MailAddress from = new System.Net.Mail.MailAddress(s_from);// '發件箱地址
            System.Net.Mail.MailAddress mto = new System.Net.Mail.MailAddress(s_to);// '收件箱地址
            System.Net.Mail.MailMessage mailobj = new System.Net.Mail.MailMessage(from, mto);

            // '完善MailMessage对象
            mailobj.Subject = m_title; //'主題
            mailobj.Body = m_body;// '郵件內容
            mailobj.IsBodyHtml = true;//
            mailobj.BodyEncoding = System.Text.Encoding.GetEncoding("UTF-8");
            mailobj.Priority = System.Net.Mail.MailPriority.Normal;

            if (m_file.Trim() != "")// '附件
            {
                mailobj.Attachments.Add(new System.Net.Mail.Attachment(m_file));
            }

            // '构建SmtpClient对象
            System.Net.Mail.SmtpClient smtp = new System.Net.Mail.SmtpClient("*.*.*.*");
            smtp.UseDefaultCredentials = false;
            smtp.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;

            try
            {
                smtp.Send(mailobj);
                return "1";
            }
            catch (System.Net.Mail.SmtpException ex)
            {
                return ex.Message;
            }
        }