Snooze functionality became my most important feature after using Mailbox. I switched to Outlook several months ago because it supports snoozing and archiving with the same swipe gestures, and it allows me to add all of the mail accounts Mailbox didn't support. The UX isn't quite as polished as Mailbox's, but that's improving regularly.

Maybe Inbox from Google? That's all I can think of at the moment. I am as sad as you are. I felt like I had absolute control over my email with no messages in the inbox and being able to snooze messages to check later.

I was a die-hard Sparrow user when that was killed. I've been using Inbox now since it came out, and it mostly fits the bill. I wish there was a desktop app like Sparrow, but the browser UI is decent. I still have to open gmail occasionally to make filters, but that's all.

I've been using Spark from Readdle for a while. It has customizeable swipe actions, so I was able to make it mimic Mailbox quite well. Has some other cool features too.