Yes, it had gotten really bad. "The inbox is not a to-do list." I need to make that my new mantra. Also, reading on my phone is was a big contributor, because I'd read something, not want to try to one-finger-type a response, and then it gets set aside and semi-forgotten.
Anyway, you may hear more about this project. Feel free to join in. Clearing the massive inbox was a HUGE weight off my shoulders when I did, well worth the investment of time.