code: public MimeMessage createMimeMessage(Session session) throws MessagingException {
  		if (isEmpty(htmlPart) && isEmpty(textPart)) {
  			throw new IllegalArgumentException("Missing email content");
  		}
  		final MimeMessage msg = new MimeMessage(session);
  		msg.setSubject(subject);
  		msg.setFrom(new InternetAddress(from));
  		msg.setContent(createMultiPart());
  		msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipients, false));
  		return msg;
  	}
docs: Creates a MimeMessage containing given Multipart.
  Subject, sender and content and session will be set.
  @param session current mail session
  @return MimeMessage without recipients
  @throws MessagingException