title: Property "mail.imap.starttls.enable", "true" doesn't work
body: <p>It is said in Oracl sslnotes, that STARTTLS command should be enabled by using mail.imap.starttls.enable or mail.smtp.starttls.enable, to "true".
  "When set, if the server supports the STARTTLS command, it will be
  used after making the connection and before sending any login
  information". So, I set this as suggested:
  </p>
  
  <pre><code>props.setProperty("mail.imap.starttls.enable", "true");
  props.setProperty("mail.store.protocol", "imap");
  props.setProperty("mail.imap.auth", "true");
  props.setProperty("mail.imap.host", "imap.mail.ru");
  
  Session session = Session.getInstance(props, new javax.mail.Authenticator() {
      protected PasswordAuthentication getPasswordAuthentication() {
          return new PasswordAuthentication(login + "@" + server, passwd);
      }
  });
  
  session.setDebug( true);
  Store store = session.getStore();
  
  store.connect();
  </code></pre>
  
  <p>but here's the dialogue:</p>
  
  <pre><code>* OK Welcome
  A0 CAPABILITY
  * CAPABILITY IMAP4rev1 ID XLIST UIDPLUS UNSELECT MOVE STARTTLS LIST-STATUS LOGINDISABLED
  A0 OK CAPABILITY completed
  A1 LOGIN tester@mail.ru tester   &lt;==== this string is edited
  A1 NO [PRIVACYREQUIRED] Command disabled. Please use STARTTLS first.
  </code></pre>
  
  <p>As I understand there's no STARTTLS command sending by connect function (though that command should be send "after making connection and before sending any login information", as it promised in Oracle manual). So what should I do to make code send this STARTTLS? </p>