If you are a Gmail user and are interesting in knowing what your email habits are, here is a tool called Gmail Meter that you may want to take look at. It’s a tool written in Google Apps Script that provides some kinds of stats that will help you analyze your email habit with Gmail.
To set up, go to your Google Docs and open or create a new spreadsheet. Click on Tools -> Script gallery, and search for “Gmail Meter”, and click Install. A new menu item called Gmail Meter will show up in the top menu bar next to Help menu. Click on it, and choose Get a report.
The Gmail Meter runs on the first day of every month and sends you an email with all the desired statistics on your own email behaviors.
You can also check out the following video for a live show how to get it work.