See home page at http://www.vanheusden.com/mboxstats/.

mboxstats creates top-10 lists from an mbox-format archive, for example:

Top writes
Top receivers
Top subjects
Top cc'ers
Top top-level-domain
Top timezones
Top organisations
Top useragents (mailprograms)
Top month/day-of-month/day-of-week/hour
Average number of lines per message
All kinds of per-user statistics
And much more! 

Since mboxstats doesn't have its own README, I made this one based on http://www.vanheusden.com/mboxstats/. As far as I can tell, the author does not keep the mboxstats source code in a public version control repository. The first Conservatory import was based on version 3.0 from http://www.vanheusden.com/mboxstats/mboxstats-3.0.tgz in Dec 2013. Later, the changes for version 3.1 were brought in on 17 Oct 2014 (see commit 964f42edd45 and commit e1f8931d41a), based on http://www.vanheusden.com/mboxstats/mboxstats-3.1.tgz.

On the web site, the author asks people to report usage of mboxstats: http://www.vanheusden.com/mboxstats/feedbackform.php?subject=mboxstats

The usual:

$ make
$ make install

You'll get a lot of warnings on the make step; just ignore them.

Cute trick: if you want to let the author know you're using mboxstats, you can apparently run

$ make thanks

After building, run

$ ./mboxstats -h

to see usage instructions.

I suggest using the author's feedback from, rather than bug reports attached to this repository, to send feedback about mboxstats:

http://www.vanheusden.com/mboxstats/feedbackform.php?subject=mboxstats

-Karl Fogel (@kfogel) [not the author of mboxstats, merely the repository assembler]