Airmail doesn't support snoozing, but it does have a unified inbox and nice UI. IMO it's a bit overloaded with power and features, but it's worth consideration.

Airmail doesn't support snoozing, but it does have a unified inbox and nice UI. IMO it's a bit overloaded with power and features, but it's worth consideration. Another commenter pointed out that you can try/use the full version for free in their beta program.