LocalInbox runs its AI on your Mac with Apple Intelligence, Apple's on-device model. Summaries, suggested replies, Rewrite, Draft with AI and Ask your mailbox all run locally. No message text is sent to an AI provider, and LocalInbox has no server of its own, so nobody else reads your mail to make it smart.
Needs macOS 26 with Apple Intelligence. Without it, this feature is hidden and everything else works.
What the on-device model does
- A one-line summary of each unread conversation in the message list, plus key points in the context panel.
- Three suggested replies written in your style.
- Rewrite a reply: shorter, friendlier, more formal, or with the grammar fixed.
- Draft with AI: describe the email (“ask Aditi to move the review to 3 pm”) and LocalInbox writes it, subject and all, with [placeholders] for details it doesn't know.
- Action cards that propose a Calendar event or a Reminder. Nothing is added until you confirm.
- Ask your mailbox: questions answered from your own mail, with numbered sources.
Rules first, the model only where it helps
Every message is decided on arrival: category, needs reply, urgency, deadline, meeting, cold outreach, spam and phishing. Fast local rules do almost all of it, in about 0.3 ms per message on average.
The model is asked only where it adds something: filing mail into categories you describe in plain words, and giving a second opinion on suspected phishing. When you move a message, that correction applies to the sender from then on.
What leaves your Mac
Your mail goes between your Mac and your mail provider, and nowhere else. The AI features open no connections of their own. macOS may download Apple's language assets for the model itself; that is Apple's system service, not LocalInbox.
Every connection the app can make is listed on the privacy and security page.
Questions
Which AI model does LocalInbox use?
Apple's on-device foundation model, through Apple Intelligence on macOS 26. Text recognition in attachments uses Apple's Vision framework, and Ask your mailbox uses on-device sentence embeddings. All of it runs on your Mac.
Is my email used to train AI?
No. LocalInbox has no server and sends no message text anywhere, so there is nothing to train on. Your corrections stay on your Mac.
What if my Mac doesn't have Apple Intelligence?
LocalInbox works on macOS 15 and later. Without Apple Intelligence, summaries, suggested replies, Rewrite, Draft with AI and Ask are hidden. Sorting rules, the To Reply mailbox, phishing warnings, search and everything else still work.