How to Run an LLM Locally on Apple Silicon to Write Emails Privately

BLUF: To run an LLM locally on Apple Silicon to write emails privately, install a local model runtime like Ollama, pull a small or mid-size open model, and connect it to a menu-bar writing tool — after that, every email you draft, polish, or reply to is processed on your Mac and nothing leaves the device. Apple's M-series chips have enough unified memory and neural throughput to run capable models offline, so privacy-minded Mac power users get clear, natural email help without sending a single word to a server. The fastest setup pairs Ollama with a tool like Nugumi pointed at the local engine.

What "running an LLM locally" actually means

Running a local LLM for email writing on Mac means the model file lives on your own machine and all the generation happens on your hardware. There is no API call, no remote server, and no log of your email sitting on someone else's computer. Once the model is downloaded, it keeps working with the network turned off entirely. This is the core of a private, offline email assistant: the text never travels, so there is nothing to intercept, retain, or leak.

Why Apple Silicon is built for this

Apple Silicon (M1, M2, M3, and later) uses unified memory, which lets the GPU and neural engine reach the same fast memory pool the CPU uses. That design is unusually good for on-device AI, because model weights and the working context sit in shared memory instead of shuffling across a slow bus. In practice, an 8GB Mac runs small models smoothly, while 16GB or more comfortably handles the mid-size models that write good email. You do not need a discrete GPU or a workstation — a recent MacBook is enough.

What you need to get started

Three pieces: a Mac on macOS 14 or later, a local runtime, and one model. Ollama is the standard runtime — it downloads open models and serves them on your machine with a single command. To run Ollama on an Apple Silicon Mac, install it, then pull a model such as a small Llama or Qwen variant; the download happens once, then runs offline forever after. From there, a menu-bar writing tool sends your selected text to that local model and shows the result inside whatever app you are in.

How local email writing actually works

A good on-device setup covers three jobs without exporting your text. Understand: select a confusing sentence in an email and get a plain-words explanation, so jargon stops slowing you down. Rewrite: polish your own draft so it reads clear, natural, and professional while keeping your meaning. Reply: draft a response to a message in your own style, then edit to taste. With a tool pointed at a local model, each of these runs entirely on your Mac — the same workflow a private AI writing assistant that works offline provides, tuned for the inbox.

Choosing a model size for your Mac

Match the model to your memory. On 8GB, stick to small models (roughly 3-4B parameters) for fast, lightweight rewriting and replies. On 16GB, a 7-8B model gives noticeably better tone and reasoning while staying responsive. On 32GB or more, you can run larger models for the hardest drafts. If quality ever falls short, step up one size before reaching for the cloud; the local LLM for writing on Mac guide breaks down the trade-offs in more detail.

Local vs cloud: keep the choice per email

Offline is the right default for anything sensitive — client names, contracts, legal language, or unreleased plans. Cloud models (a ChatGPT or Claude subscription, or your own API key) still edge ahead on the hardest reasoning, and they need no local hardware. The smart approach is to match the engine to the email: local for confidential drafts, cloud when raw polish matters more than secrecy. A tool that lets you switch between the two without changing your workflow gives you both, so the private path stays the easy default.

Set it up in a few minutes

Install Ollama, pull one model, and point your writing tool at it; the download page covers the Mac steps for Nugumi, which is free during early beta with no signup or account. Test it on real email first — rewrite a message, explain a tricky paragraph, draft a reply — and confirm the quality fits before you depend on it. Once it does, you have a private, offline email assistant on your own Apple Silicon Mac, with every word staying exactly where you wrote it.