I've checked the installation directory. So i've written a method like
this:

<code>
 private void sendMail() {
   MainFrame.get().setCursor(Preferences.WAIT_CURSOR);
   String adr = address.getText();
   try {
     // create properties
     Properties props = System.getProperties();
     props.put("mail.smtps.auth", "true");
     props.put("mail.smtps.port", "25");
     props.put("mail.smtps.host", Preferences.MAIL_HOST);
     // create session
     Session session = Session.getDefaultInstance(props);
     session.setDebug(true);
     // create content
     MimeMultipart content = new MimeMultipart("alternative");
     // Text Mail
     MimeBodyPart plain = new MimeBodyPart();
     plain.setContent(plainText, "text/plain");
     plain.setHeader("MIME-Version", "1.0");
     plain.setHeader("Content-Type", "text/plain;
charset=\"iso-8859-1\"");
     content.addBodyPart(plain);
     // HTML Mail
     MimeBodyPart html = new MimeBodyPart();
     html.setContent(htmlText, "text/html");
     html.setHeader("MIME-Version", "1.0");
     html.setHeader("Content-Type", "text/html;
charset=\"iso-8859-1\"");
     content.addBodyPart(html);
     // create message
     MimeMessage msg = new MimeMessage(session);
     msg.setContent(content);
     msg.setHeader("MIME-Version", "1.0");
     msg.setHeader("Content-Type", content.getContentType());
     msg.setHeader("X-Mailer", "Java-Mailer");
     msg.setSentDate(new Date());
     // set sender and recipient
     msg.setFrom(new InternetAddress(Preferences.MAIL_FROM,
         Preferences.MAIL_SENDER));
     msg.addRecipient(Message.RecipientType.TO, new
InternetAddress(adr));
     msg.setSubject(Texts.MAIL_SUBJECT);
     // save changes
     msg.saveChanges();
     // transport the message
     SMTPSSLTransport transport =
(SMTPSSLTransport)session.getTransport("smtps");
     // get password
     String pwNew = DataManager.code(Preferences.MAIL_PASSWORD);
     // connect to server
     // send the message
     transport.connect(Preferences.MAIL_HOST, Preferences.MAIL_LOGIN,
pwNew);
     transport.sendMessage(msg, msg.getAllRecipients());
     // close the connection
     transport.close();
   } catch (Exception e) {
     e.getStackTrace();
     ErrorManager.mailError(MainFrame.get());
     return;
   } finally {
     MainFrame.get().setCursor(Preferences.DEFAULT_CURSOR);
     dispose();
   }
   ErrorManager.mailSent(MainFrame.get());
 }
</code>

But this isn't working (Yes the port 25 is ok for ssl connection, with
Mail.app this account is working).

Here the debug stack trace:
DEBUG: setDebug: JavaMail version 1.4ea
DEBUG: getProvider() returning
javax.mail.Provider[TRANSPORT,smtps,com.sun.mail.smtp.SMTPSSLTransport,Sun
Microsystems, Inc]
DEBUG SMTP: useEhlo true, useAuth true
DEBUG SMTP: trying to connect to host "xxx-my.mail.host-xxx", port 25,
isSSL true
DEBUG SMTP: exception reading response: javax.net.ssl.SSLException:
Unrecognized SSL message, plaintext connection?

Bug? Or am i blind?

Best regards

Carsten