code: private Multipart createMultiPart() throws MessagingException {
  		Multipart multipart = new MimeMultipart("alternative");
  		if (textPart != null) {
  			// add text first, to give priority to html
  			multipart.addBodyPart((BodyPart) createTextMimePart());
  		}
  		if (htmlPart != null) {
  			multipart.addBodyPart((BodyPart) createHtmlMimePart());
  		}
  		return multipart;
  	}
docs: Creates a Multipart from present parts.
  @return multipart with all present parts
  @throws MessagingException