mls will read mailbox file in MBOX format and display various
statistical data about it. You can specify input and ouput files (can
be stdin/stdout), language used for output (in this version
Slovak/English/Italian/Francais/Deutsch/Spanish/Serbian), error and
diagnostic msgs are always printed in english. You can also specify
text which will be displayed instead of standart title in output (can
be used for automatic mailing of produced output).

It also supports cache file for faster re-generation of stats from the
same input file. It is useful when you want to show statistics on web
- you can use HTML output & PHP wrapper.