fang1004tw

        //這段一定要, 跳過憑證無效用的
        public static bool ValidateServerCertificate(Object sender, X509Certificate certificate, X509Chain chain, System.Net.Security.SslPolicyErrors sslPolicyErrors)
        {
            return true;
        } 

        private void simpleButton2_Click(object sender, EventArgs e)
        {
            // 這段一定要, 要寫這個才可以跳過 "根據驗證程序,遠端憑證是無效的" 的錯誤
            System.Net.ServicePointManager.ServerCertificateValidationCallback = 
                new System.Net.Security.RemoteCertificateValidationCallback(ValidateServerCertificate);

            
            System.Net.Mail.SmtpClient smtpClient = 
                new System.Net.Mail.SmtpClient("xxxxx.xxxxxx.xxx.com"); // 365 主機, 在365 outlook 設定中個人郵件設定
            smtpClient.Port = 587; // 365 好像都是用587 
            smtpClient.EnableSsl = true;  //這一定要設 true
            System.Net.NetworkCredential credentials = 
                new System.Net.NetworkCredential("xxxx@xxxmicrosoft.com", "xxxxx"); //365 帳號密碼
            smtpClient.Credentials = credentials;
            //smtpClient.ClientCertificates = false; //這行不用寫

            for (int i = 0; i < 10; i++) //連續發送10次測試效能
            {
                System.Net.Mail.MailMessage mail = new System.Net.Mail.MailMessage();
                // 寄件人這個好像不能亂寫, 一定要寫真實office 365 上面的郵箱和人名 , 不然會沒反應
                mail.From = new System.Net.Mail.MailAddress("xxxx@xxxxxxxxxxxx", "xxxxxx");
                mail.To.Add("xxxxx@gmail.com");

                mail.Subject = "office 365 " + i.ToString();
                mail.Body = "this is my message body";
                mail.IsBodyHtml = true;
                mail.Attachments.Add(new System.Net.Mail.Attachment("xxxxxxx")); //夾附件測試

                smtpClient.Send(mail); // <--發送
                mail.Dispose();
            }

            smtpClient = null;
            
        }