This has some nice tips, but seems overly complex. Try using the "Unread First" inbox, and simply mark email that you need to take action on as Unread, whether you've replied to it or not.
88 karma · joined April 26, 2013
Google Apps Business/Education customers enjoy a 2000 daily limit btw :) http://support.google.com/a/bin/answer.py?hl=en&answer=16685...