Kestrel Mail

Documentation

Acknowledgements

The open-source projects and Apple frameworks used by Kestrel Mail.

Updated August 28, 2026

App foundations

  • SwiftMail provides IMAP and SMTP support.
  • SwiftSoup parses and sanitizes message HTML.
  • Sparkle handles signed software updates for direct-download releases.
  • llama.cpp runs the optional local model pack.

Website

  • Astro builds this site.

Apple platform

Kestrel uses SwiftUI, WebKit, Quick Look, Contacts, Foundation Models, Keychain, and Apple's authentication APIs.

Thank you

To the maintainers and platform teams behind these tools: thank you.