The ablity for the user to customize their inbox - with options of the old inbox with optional new features.
The problem is, the inbox is too busy looking. With ads constantly popping up, computers are freezing, and the inbox is extremely bulky-looking. It's hard to differentiate an actual email from an Ad. Its cluttered and not user-friendly. No, I do not care about "rewards" for reading and sending emails. That is a horrible concept and should be discontinued.
62nd
ranked