邮件发送程序可以通过我的电子邮件发送邮件吗？

Question

我有一个代码，它始终通过邮件pec发送到Aruba上。 有一次，它不再起作用了。当我编译时，它返回：

Exception reading response
Exception reading response
Exception reading response
Exception reading response
Exception reading response
Exception reading response
Exception reading response
Exception reading response
Exception reading response

使用嗅探程序，我发现问题与“认证未知”有关。

这是我的代码：

//********************************************************
    public static boolean sendMail(String Messaggio, String mailDest) {
        boolean stato = true;
        try {
            stato = true;
            DataHandler dh = null;
            Properties props = System.getProperties();
            props.put("mail.smtp.host", Main.conf.getSmtp());
            //attivare pec
            props.put("mail.smtp.socketFactory.port", "465");
            props.put("mail.smtp.socketFactory.class","javax.net.ssl.SSLSocketFactory");
            props.put("mail.smtp.auth", "true");
            props.put("mail.smtp.port", "465");

            Session session = Session.getDefaultInstance(props, authenticator );            
            javax.mail.Message message = new MimeMessage(session);
            InternetAddress from = new InternetAddress(Main.conf.getMittenteMail());            
            InternetAddress to[] = InternetAddress.parse(mailDest);

            message.setFrom(from);
            message.setRecipients(javax.mail.Message.RecipientType.TO, to);
            message.setSubject("AVVISO DI SCADENZA RIBA");
            message.setSentDate(new Date());

            // NUOVA GESTIONE MAIL : Testo + Allegato

            Multipart multipart = new MimeMultipart();
            // crea la parte testuale
            BodyPart messageBodyPart1 = new MimeBodyPart(); 
            messageBodyPart1.setContent(Messaggio.toString(),"text/html"); 
        //  messageBodyPart1.setText(Messaggio);

            //  Crea l'allegato , disattivata.
            //  DataSource source = new FileDataSource(file);
          //BodyPart messageBodyPart2 = new MimeBodyPart(); 
        //  messageBodyPart2.setContent("<b>Sollecito Riba:<\b>", "text/html");
            //  mp.addBodyPart(bpHTML)

            // messageBodyPart2.setDataHandler(new DataHandler(source));

            /*File fFile = new File("C:\\folder\\prova.txt");
            DataSource source = new FileDataSource(fFile);  ALLEGATO
            dh = new DataHandler(source);
            messageBodyPart2.setDataHandler(dh);
            messageBodyPart2.setFileName(fFile.getName());
*/
            // aggiunge le parti all'oggetto multipart
            //multipart.addBodyPart(messageBodyPart2);
            multipart.addBodyPart(messageBodyPart1); //html
            //multipart.addBodyPart(messageBodyPart2);

            // imposta come contenuto del messaggio l'oggetto multipart
            message.setContent(multipart);
            // Transport.send(message);
            // FINE NUOVA GESTIONE: Testo + Allegato

            javax.mail.Transport.send(message);
        } catch (MessagingException e) {
            stato = false;
            System.out.println(e.getMessage());
        }
        return stato;
    }

我该怎么办？发生了什么？为什么它有效但不再有效？