发送电子邮件在测试中有效,但在生产中无效

我在应用程序中创建了此函数。当我测试它时,它工作得很好。当我发布应用程序时,不会发送电子邮件。有人知道会发生什么吗?

在生产中,该代码也可以工作,不会显示任何错误消息。但是,不会发送电子邮件。在本地测试环境中,电子邮件可以完美地发送。我相信代码不是问题所在。我想某些配置会阻止您在生产中使用此功能。

我在这个问题上做了很多研究,没有发现任何有用的东西。

我正在使用Android Studio,JAVA。

非常感谢。

 private void enviaEmailBoasVindas() {

        Connection ipp_CON_CONNEC;
        String Mail_Username = "";
        String Mail_Password = "";
        String Mail_Destino = "";
        String Mail_Copia = "";
        String Mail_Message = "TESTE";
        Mail_Message = Mail_Message.replace("[USERNAME]", iPPData.getNomeCompleto().toString().trim());
        try {
            ipp_CON_CONNEC = iPPdb.AbreConexao();
            if (ipp_CON_CONNEC != null) {
                String ipp_STR_SQLQRY = "myquery";
                if (ipp_RES_DATSET.next()) {
                    do {
                        Mail_Username = ipp_RES_DATSET.getString("tbdata1").toString().trim();
                        Mail_Password = ipp_RES_DATSET.getString("tbdata2").toString().trim();
                    } while (ipp_RES_DATSET.next());
                }
                ipp_CON_CONNEC.close();
            }
        } catch (SQLException throwables) {
            String erro = throwables.getMessage();
        }

        Mail_Destino = iPPData.getUserEmail();
        Mail_Copia = "xxxxxxxxx@gmail.com";

        Properties props = new Properties();
        props.put("mail.smtp.auth", true);
        props.put("mail.smtp.starttls.enable", true);
        props.put("mail.smtp.host", "smtp.gmail.com");
        props.put("mail.smtp.port", "587");
        String finalMail_Username = Mail_Username;
        String finalMail_Password = Mail_Password;
        Session session = Session.getInstance(props,
                new javax.mail.Authenticator() {
                    @Override
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication(finalMail_Username, finalMail_Password);
                    }
                });
        try {
            Message message = new MimeMessage(session);
            message.setFrom(new InternetAddress(Mail_Username));
            message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(Mail_Destino));
            message.setRecipients(Message.RecipientType.BCC, InternetAddress.parse(Mail_Copia));
            message.setSubject("xxxxxxxxxxxx");
            message.setText(Mail_Message);
            Transport.send(message);
        } catch (MessagingException e) {
            // error
        }
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);

        Statement ipp_STA_SQLSTA;
        ResultSet ipp_RES_DATSET;
        String ipp_STR_SQLQRY = "";
        String currentTime = new SimpleDateFormat("HH:mm", Locale.getDefault()).format(new Date());

        String tTitulo = "title";
        String tTexto = "text";

        try {
            ipp_STR_SQLQRY = "myquery";
            ipp_CON_CONNEC = iPPdb.AbreConexao();
            ipp_STA_SQLSTA = ipp_CON_CONNEC.createStatement();
            ipp_STA_SQLSTA.execute(ipp_STR_SQLQRY);
        } catch (Exception e) {
            SetMessage("Erro Complemento", e.toString() + " / " + ipp_STR_SQLQRY);
        }
    }