Jeff Reifman's posted a video explaining more about his next-generation IMAP-filtering email project, Simplify Email.
* Report of who sends you the most email by week, month, year
* Report of who you email the most by week, month, year
* Report of unanswered emails that have not been replied to
* Report of emails that you've not replied to
* Easy new ways to train your filters, including analysis of your sent mail