parts ("attachments") all parts are decoded. Decoding can be controlled by
command-line options.
+WHAT'S NEW in version 2.3.4 (2014-02-11)
+
+ Optimize recursive decoding.
+
+ Fix a bug - decode message/rfc822 subparts.
+
WHAT'S NEW in version 2.3.3 (2014-02-02)
Forbid filtering from console. When the program runs with stdin
connected to the console it shows usage help.