Error: The SMTP server requires a secure connection or the client was not authenticated.

繼上次Sending Email這篇文章後，開始把網頁發佈上Azure，卻發現出錯了！

錯誤訊息為：

Error: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required.

因為伺服器位置的關係，Google判定Azure Website連安全性較低的應用程式都不算！

所以Google就提供了「應用程式專用密碼」來解決這個安全性問題，步驟如下：

1.先連結到Google帳號設定頁面

2.點選兩步驟驗證→開始設定

3.通過手機認證

4.認證完後，回到一開始Google帳號設定頁面，選擇應用程式密碼→設定

5.選擇你的應用程式，或自訂名稱

6.按產生密碼

7.複製密碼!

8.使用剛剛產生的密碼寄送EMAIL

async public Task< string> SendEmailAsync(  )

       {           

            string emailFrom = "xxx@gmail.com"; //"email@yahoo.com";

            string password = "剛剛複製的應用程式密碼";

            string emailTo = //"someone@domain.com";

            string subject = "Wecare診所檢驗提醒" ;//"Hello";

            string body = "內容";  "Hello, I'm just writing this to say Hi!";

            using ( MailMessage mail = new MailMessage())

            {

                try

                {

                    mail.From = new MailAddress(emailFrom);

                    mail.To.Add(emailTo);

                    mail.Subject = subject;

                    mail.Body = body;

                    mail.IsBodyHtml = false;

                    // Can set to false, if you are sending pure text.

                    //mail.Attachments.Add(new Attachment("C:\\SomeFile.txt"));

                    //mail.Attachments.Add(new Attachment("C:\\SomeZip.zip"));

                    using ( SmtpClient smtp = new SmtpClient())

                    {

                        smtp.Host = "smtp.gmail.com";

                        smtp.Port = 587;

                        smtp.UseDefaultCredentials = false;

                        smtp.Credentials = new NetworkCredential(emailFrom, password);

                        smtp.EnableSsl = true;

                        await smtp.SendMailAsync(mail);

                    }

                }

               

               catch(Exception e) { MessageBox.Show(e.ToString()); }

                return "檢驗提醒EMail已發送!" ;

            }          

        }   

最後發布到雲端就大功告成囉！