What is Kestrel Mail?
Kestrel Mail is a native macOS mail client focused on a fast, keyboard-first experience, support for more than one provider, and privacy-conscious local AI features.
Which accounts does it aim to support?
The target is Gmail, Microsoft 365, and generic IMAP accounts. The product direction is universal IMAP support with provider-specific sign-in where it improves setup.
What version of macOS does Kestrel Mail target?
The current app targets macOS 26 and newer. That may evolve over time, but the present baseline is macOS 26 or later.
Does it work offline?
Kestrel Mail is being built with cache-first reads, local-first draft saves, and a durable remote mutation queue so the app stays useful even when connectivity is unreliable. Some actions still depend on reconnecting before the remote server can reflect them.
How do summaries work?
Kestrel supports on-device message and thread summaries. Apple Foundation Models is the default path when it is available, and an optional enhanced local model pack can be used when installed and ready.
Does Kestrel send my email content to a cloud AI service?
The intent is to keep summarization local to the device. Network activity is still part of normal mail sync and account authentication, and downloading an optional local model pack also requires the network, but the summaries themselves are designed to stay on device.
Is the full public site ready yet?
Not yet. The current root site is intentionally minimal while the brand, imagery, and broader launch story are still being finalized. The docs surface is live now so the app has stable URLs for reference material.
Where can I find third-party acknowledgements?
The public acknowledgements page lives at /docs/acknowledgements/.