JavaMail sending mail attachment from string - encoding UTF-8

This is a sample code that I use to send files (irrespective on encoding or data structure).

BodyPart fileBodyPart = new MimeBodyPart();
fileBodyPart.setDataHandler(new DataHandler(fileDataSource));
fileBodyPart.setFileName(attachment.getName());
fileBodyPart.setHeader("Content-Type", fileDataSource.getContentType());
fileBodyPart.setHeader("Content-ID", attachment.getName());
fileBodyPart.setDisposition(Part.INLINE);

Where fileDataSource is a javax.activation.DataSource (text file will be in here), and fileBodyPart.setDisposition(Part.INLINE); (PART.INLINE means datasource is inlined with the message body, just like HTML emails, PART.ATTACHMENT means datasource is an attachment).

Hope this helps.

Set the content type to application/octet-stream:

MimeBodyPart attachmentPart = new MimeBodyPart();

try {
  DataSource ds = new ByteArrayDataSource(attachment.getBytes("UTF-8"), "application/octet-stream");
  attachmentPart = new MimeBodyPart();
  attachmentPart.setDataHandler(new DataHandler(ds));
} 
catch (Exception e) {
  Logger.getLogger("Blina").log(Level.SEVERE, Misc.getStackTrace(e));
}

attachmentPart.setFileName(fileName);
multipart.addBodyPart(attachmentPart);

// Put parts in message
msg.setContent(multipart);

If problem is in file name, rather than in body, following code helped in my (hebrew) case:

MimeBodyPart attachment = new MimeBodyPart();
attachment.setFileName(MimeUtility.encodeText(filename, "UTF-8", null));

Had similar case, following code solved it:

MimeBodyPart att = new MimeBodyPart();
att.setFileName(MimeUtility.encodeText(fileName));