OutputStreamWriter out = new OutputStreamWriter(new ByteArrayOutputStream());
System.out.println(out.getEncoding());

MimeMessage msg = new MimeMessage(session);
    MimeBodyPart mbp1 = new MimeBodyPart();
    mbp1.setDataHandler(new DataHandler(new ByteArrayDataSource(message.toString, "text/html")));
    mbp1.setContent(new String(message.getBytes("UTF-8"),"ISO-8859-1"), "text/html");
    Multipart mp = new MimeMultipart();
    mp.addBodyPart(mbp1);
    msg.setContent(mp, "text/html");