-Extend options -eIi to multipart subparts.
-
-
-Never touch multipart/encrypted and multipart/signed (but allow -I).
+Never decode subparts of multipart/encrypted and multipart/signed messages but
+allow processing of headers of the top-level part, ignoring the top-level part
+with -I, aborting it with -e or saving the part or subparts with --save-*.