Hi, My multiple mail attachment is in form of input stream along with message body. Here is code : DataHandler dataHandler = new DataHandler( inputstream, "application/octet-stream" ); DataContentHandlerFactory dchf = new SimpleDCF("application/octet-stream:com.util.PlainDCH "); MimeBodyPart.setDataHandler(dataHandler); message.setContent(multipart); Above I have made use of 2 classes SimpleDCF,PlainDCH given in Demo example of javamail-1.3 . Mime type is application/octet-stream to support all file type attachments. Mail with attachment is going. But the attachment is not opening.    More>>