\fpart{ ID: 4, Content-type: text/plain
This is a test encrypted message.
\fpart}
-\fattachment{ ID: 5, Content-type: application/octet-stream
-Attachment: TESTATTACHMENT (application/octet-stream)
+\fattachment{ ID: 5, Filename: TESTATTACHMENT, Content-type: application/octet-stream
Non-text part: application/octet-stream
\fattachment}
\fpart}