multipPartRoot.addBodyPart(contentPartRoot);
for (Attachment att : attachment)
{
InputStream is = att.getInputStream();
MimeBodyPart mimeBodyPart = new MimeBodyPart();
ByteArrayDataSource byteArrayDataSource = new ByteArrayDataSource(is, att.getMimeType());
mimeBodyPart.setDataHandler(new DataHandler(byteArrayDataSource));
mimeBodyPart.setDisposition(Part.ATTACHMENT);
if (att.getName() != null)
mimeBodyPart.setFileName(MimeUtility.encodeText(att.getName(), "utf-8", null));