The short answer is that (1) email wasn't designed to be instantaneous, and (2) it uses a distributed protocol. One of our goals is to make transit as fast as

The short answer is that (1) email wasn't designed to be instantaneous, and (2) it uses a distributed protocol. One of our goals is to make transit as fast as possible. But there's a limit to what Inbox can do right now since it works on top of existing providers, like Gmail or Yahoo! Mail.