JavaMail API has trouble to work with the Gmail

Question

I'm working on the tutorial at http://www.oracle.com/webfolder/technetwork/tutorials/obe/java/javamail/javamail.html which shows how to send email with JavaMail API.

So I wrote the following code snippet

public class EmailSessionBean {

private int port = 465;
private String host = "smtp.gmail.com";
private String from = "[email protected]";
private boolean auth = true;
private String username = "[email protected]";
private String password = "mypassword";
private Protocol protocol = Protocol.SMTPS;
private boolean debug = true;

public void sendEmail(String to, String subject, String body) {

    // Create a Properties object to contain settings for 
    // the SMTP protocol provider.
    Properties props = new Properties();
    props.put("mail.smtp.host", host);
    props.put("mail.smtp.port", port);
    switch (protocol) {
        case SMTPS:
            props.put("mail.smtp.ssl.enable", true);
            break;
        case TLS:
            props.put("mail.smtp.starttls.enable", true);
            break;
    }

    // If SMTP authentication is required you must set the mail.smtp.auth 
    // property and construct a Authenticator instance that returns 
    // a PasswordAuthentication instance with your username and password. 
    Authenticator authenticator = null;
    if (auth) {
        props.put("mail.smtp.auth", true);
        authenticator = new Authenticator() {
            private PasswordAuthentication pa
                    = new PasswordAuthentication(username, password);

            @Override
            public PasswordAuthentication getPasswordAuthentication() {
                return pa;
            }
        };
    }

    //Create a Session instance using the Properties object 
    // and the Authenticator object.
    Session session = Session.getInstance(props, authenticator);
    session.setDebug(debug);

    // Construct a MimeMessage instance, populate the message headers 
    // and content and then send the message
    MimeMessage message = new MimeMessage(session);
    try {
        message.setFrom(new InternetAddress(from));
        InternetAddress[] address = {new InternetAddress(to)};
        message.setRecipients(Message.RecipientType.TO, address);
        message.setSubject(subject);
        message.setSentDate(new Date());
        message.setText(body);
        Transport.send(message);
    } catch (MessagingException ex) {
        ex.printStackTrace();
    }
}
}

When I try to send Email with the WEB APP, Gmail stops me from doing that and mail me "Sign-in attempt prevented".

P.S. I also disabled the "Access for less secure apps" in my Gmail account. But in the next attempt for doing that Gmail suspended my Account.

Any useful comment/solution will be appreciated.

Answer 1

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