[djcb]

I wrote 'mu' (http://www.djcbsoftware.nl/code/mu), which let's you index/search maildirs; I'm currently adding glue to use it as an emacs-based e-mail client as well (basically, something between wanderlust and notmuch).

Anyway, to get back on-topic, as an alternative way to analyse your mails, I've added guile (scheme) bindings, and it's pretty easy to get all kinds of interesting statistics from your mails -- see https://gitorious.org/mu/mu/blobs/master/toys/muile/README