Rather than using IMAP, we integrate with Gmail's APIs from our servers. This allows us to have a new client-server protocol that supports a bunch of new stuff -- like faster real-time updates, better latency compensation and offline handling, bundled inboxes, more interesting triage flows, emoji reactions, presence, etc.

The downside of this is obviously that we have to do a customer integration with Gmail to do this. But fortunately it's not too complex, and we intend to support other services in the future. And maybe, in the _long term_, improve the protocols so this integration can be more standard.