How do I properly setup javamail to use STARTTLS?

Question

When setting up my session I am setting the starttls.enable and .required properties but when the connection happens it should fail according to the documentation:

mail.smtp.starttls.enable boolean If true, enables the use of the STARTTLS command (if supported by the server) to switch the connection to a TLS-protected connection before issuing any login commands. Note that an appropriate trust store must configured so that the client will trust the server's certificate. Defaults to false." http://javamail.kenai.com/nonav/javadocs/com/sun/mail/smtp/package-summary.html

props = new Properties();
props.put("mail.smtps.host", MAILSERV);
props.put("mail.smtps.socketFactory.port", 465);
props.put("mail.smtps.auth", "true");
props.put("mail.smtps.port", 465);
props.put("mail.smtps.socketFactory.fallback", "false");
props.put("mail.smtps.socketFactory.class","utils.DummySSLSocketFactory");
props.put("mail.smtps.quitwait", "false");
props.put("mail.smtp.starttls.enable", "true");
props.put("mail.smtp.starttls.required", "true");
Session session = Session.getInstance(props, authenticator);  


transport = session.getTransport("smtps");
transport.connect(mailServer, port, username, password);
transport.sendMessage(message, message.getAllRecipients());

So what am I doing wrong that is allowing me to use Starttls when its not supported by the server?

Answer 1

The issue I was having with STARTTLS was caused by me getting a secure transport:

transport = session.getTransport("smtps");

After changing it to "smtp" i was able to use STARTTLS.