This app just came across my radar today, and I wish I had known about it a while ago. The app offers an interface that appears to fix many of the problems I see in the more common email clients.
Gmail for Android, for example, has awkwardly placed archive/delete buttons, and I believe that the stock email client on the iPad is so completely useless for dealing with even a moderate volume of emails that I won't even express a negative opinion.
But now that I have Mailbox, none of that matters.
In related news, the Mailbox team is also launching a new feature today called auto-swipe. The app will learn from how you sort your email and automatically repeat your actions on any incoming emails. Mute that discussion you don’t care about, snooze messages from your friends until after work, and route receipts to a list — automatically.
Gmail has a similar filtering option, but you have to set it up manually (and it doesn't always work). I can't wait to try Mailbox and see how it improves on Gmail.