Javamail: 电子邮件已从程序中成功删除，但未送达 Windows Server 2012 r2

    String port = "26";

        // Recipient's email ID needs to be mentioned.

        String to = "*****@gmail.com";



        // Sender's email ID needs to be mentioned

        String host = "mail.*****.com.pk";

        String username = "sales@*****.com.pk";//change accordingly

        String password = "*****";//change accordingly



        Properties props = new Properties();

        props.put("mail.smtp.auth", "true");

        props.put("mail.smtp.host", host);

        props.put("mail.smtp.port", port);

        // SSL Factory

        // props.put("mail.smtp.socketFactory.class",

        //           "javax.net.ssl.SSLSocketFactory");

        props.put("mail.smtp.starttls.enable", "false");



        System.out.println("TLS Settings False");

        System.out.println("Sending with port: " + port);



        // Get the Session object.

        Session session = Session.getInstance(props,

                        new javax.mail.Authenticator() {

                                protected PasswordAuthentication getPasswordAuthentication() {

                                        return new PasswordAuthentication(username, password);

                                }

                        });



        try {

                // Create a default MimeMessage object.

                Message message = new MimeMessage(session);



                // Set From: header field of the header.

                message.setFrom(new InternetAddress(username));



                // Set To: header field of the header.

                message.setRecipients(Message.RecipientType.TO,

                                InternetAddress.parse(to));



                // Set Subject: header field

                message.setSubject("Testing Subject from ******.com.pk");



                // Now set the actual message

                message.setText("Hello, this is sample for to check send " +

                                "email using JavaMailAPI on personal workstation ");



                // Send message

                Transport.send(message);



                System.out.println("Sent message successfully....");



        } catch (MessagingException e) {

                throw new RuntimeException(e);

        }