How do you construct an HTML Message, with an alternative text body, and then attach a file to it with a name such as "myfile.html" ? Programs like Outlook appear to eliminate the attachment altogether or display it instead of the html message body.

Examining a raw message constructed by another mailer, I discovered that the boundry placed for the attachments differs from the boundries for the alternative message bodies. I couldn't find a way to do this with the JavaMail API.