title: UTF-8 charset doesn't work with javax.mail
body: <p>I have used <a href="https://javaee.github.io/javamail/" rel="noreferrer">Java Mail API</a>, for sending emails. I am using a contact formular to send the input, which has to be send to a specific email.</p>
  
  <p>The email is send without problems, though I am a danish guy, and I am therefore in need of three danish characters which is 'æ', 'ø' and 'å', in the subject and the email text.</p>
  
  <p>I have therefore seen that I can use UTF-8 character encoding, to provide these characters, but when my mail is send I only see some strange letters - 'ã¦', 'ã¸' and 'ã¥' - instead of the danish letters - 'æ', 'ø' and 'å'.</p>
  
  <p>My method to send the email is looking like this:</p>
  
  <pre><code>public void sendEmail(String name, String fromEmail, String subject, String message) throws AddressException, MessagingException, UnsupportedEncodingException, SendFailedException
  {
      //Set Mail properties
      Properties props = System.getProperties();
      props.setProperty("mail.smtp.starttls.enable", "true");
      props.setProperty("mail.smtp.host", "smtp.gmail.com");
      props.setProperty("mail.smtp.socketFactory.port", "465");
      props.setProperty("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
      props.setProperty("mail.smtp.auth", "true");
      props.setProperty("mail.smtp.port", "465");
      Session session = Session.getDefaultInstance(props, new javax.mail.Authenticator() {
          @Override
          protected PasswordAuthentication getPasswordAuthentication() {
              return new PasswordAuthentication("my_username", "my_password");
          }
      });
  
      //Create the email with variable input
      MimeMessage mimeMessage = new MimeMessage(session);
      mimeMessage.setHeader("Content-Type", "text/plain; charset=UTF-8");
      mimeMessage.setFrom(new InternetAddress(fromEmail, name));
      mimeMessage.setRecipient(Message.RecipientType.TO, new InternetAddress("my_email"));
      mimeMessage.setSubject(subject, "utf-8");
      mimeMessage.setContent(message, "text/plain");
  
      //Send the email
      Transport.send(mimeMessage);
  }
  </code></pre>
  
  <p>Please help me find out how I can correct this 'error'.</p>