It's keyboard-first, with split inboxes, reminders, and a built-in calendar. It's local-first, including the AI features that use local models shipped in macOS 27, with the option to use Claude/Codex subscriptions. It's extremely configurable, even down to the search weights, and comes packed with CLI/MCP if you want to use it with an agent.
This is my daily driver for email, but it's by no means a "stable" product. Use at your own risk. I'm also working on a mobile app to go along with it.
Enjoy.