-\fpart{ ID: 1, Content-type: multipart/mixed
-\fpart{ ID: 2, Content-type: text/plain
+\fpart{ ID: 1, Content-type: multipart/encrypted
+\fpart{ ID: 2, Content-type: application/pgp-encrypted
+Non-text part: application/pgp-encrypted
+\fpart}
+\fpart{ ID: 3, Content-type: multipart/mixed
+\fpart{ ID: 4, Content-type: text/plain