Netbeans 8.2-清理和构建后发送电子邮件不起作用

Question

这让我发疯了:)当我在netbeans上编码时，代码运行良好（我的意思是，它成功发送了我想要的所有电子邮件），但是，在Clean and Build之后，它只是不发送任何电子邮件

。

zzzzzzzzzzzzzzzzzzzz =我的密码

这是我的sendig代码：

private void envia_email (String email_selecionado) {

        String to = email_selecionado;
        String from = "xxxxxxxxxx@gmail.com";

        Properties properties = new Properties();
        properties.put("mail.transport.protocol", "smtp" );
        properties.put("mail.smtp.starttls.enable", "true");
        properties.put("mail.smtp.auth", "true");
        properties.put("mail.smtp.host", "smtp.gmail.com");
        properties.put("mail.smtp.port", "587");
        properties.put("mail.smtp.socketFactory.class",
            "javax.net.ssl.SSLSocketFactory"); //SSL Factory 
    try {    
        Session session = Session.getInstance(properties,
                new javax.mail.Authenticator() {
                    @Override
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication(from, "zzzzzzzzzzz");
                    }
                });

        MimeMessage message = new MimeMessage(session);
        message.setFrom(new InternetAddress(from));
        message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
        message.setSubject("EUROMILIONS PLAY SOFTWARE");
        message.setText(corpo_email.getText());
        message.setSentDate(new Date());

        Transport.send(message);
        //JOptionPane.showMessageDialog(null,"Mensagem enviada com sucesso !");
    } catch (MessagingException ex) {
        teste.setVisible(false);
        JOptionPane.showMessageDialog(this,"Erro: "+ex.toString());
        //Logger.getLogger(serial_control.class.getName()).log(Level.SEVERE, null, ex);
    }
}

有什么问题？为什么它可以在netbeans上运行，但在Clean and Build之后不能运行。

谢谢