I've used every possible email app there is including the basics (Gmail, Inbox, Spark) up to the premium ones including Canary, Hey and Superhuman. Nothing comes close - Shortwave is hands down the best email app on the planet. This app has it all - it's multi-platform, thoughtfully designed, super responsive and the email philosophy just makes sense. They've incorporated AI in the best ways that are actually designed to help (not just as a buzzword). And the features like bundling, the slide out panels, scheduled send and receive, auto-unsubscribe, inbox reorganization, keyboard shortcuts - it's insane!
They're a small but responsive team and go out of their way to make you feel good about feedback you're giving. I'm so glad I stumbled upon them - this is a team to watch and a product to use for a long long time.