AI email apps read everything in your inbox. Seven questions to ask before you connect one, and how Spark, Canary, Shortwave, Superhuman, Apple Mail and Dusk answer them.
To summarise or sort your email, an AI has to read it. All of it: contracts, medical letters, bank statements, private conversations. Before you connect an AI app to your inbox, it's worth knowing where your mail goes and who can see it.
7 questions to ask
1. Where does the AI run?
On your device, or on a server? If it's a server, your email leaves your computer every time the AI does anything.
2. Whose AI is it?
Many email apps don't run their own models. They send your email to a provider like OpenAI, Anthropic or Google. That's another company in the chain.
3. Is my mail stored, and for how long?
Some providers keep what they receive for a period, for example for abuse monitoring, even if they don't train on it.
4. Is it used for training?
Most reputable apps now say no. Check the privacy policy says so plainly.
5. Does the app have its own server in the middle?
Some apps route all your mail through their servers, not just the AI requests. That means a copy of your mailbox exists somewhere other than your provider and your device.
6. What happens if I stop paying?
Does the app keep working? Is your data deleted?
7. Can I turn the AI off?
You should be able to use the app without the AI, and switch individual features off.
How popular AI email apps compare
| App | Where the AI runs | Price for the AI |
|---|
| Dusk | Only on your Mac (Apple's on-device model) | Included in $49 once |
| Apple Mail | Your Mac, or Apple's Private Cloud Compute | Free |
| Canary Mail | Sorting on your device, writing in the cloud (OpenAI, Anthropic, Cohere, Google) | Paid plans |
| Spark | Cloud (Azure OpenAI) | Plus or Pro plan |
| Superhuman | Cloud | In the subscription |
| Shortwave | Cloud (Anthropic's Claude models) | In the subscription |
Details as each company described them in September 2026. Check their privacy pages for the latest.
Why we kept Dusk's AI on the Mac
When we built Dusk, we decided the AI would run only on the Mac, with no cloud fallback and no Dusk server between you and your mail. Dusk talks to Google and iCloud directly from your Mac. Sorting, summaries, digests and reply drafts all use Apple's on-device model, and they still work offline. There's no analytics. The trade-off is a smaller model than the cloud giants, which is plenty for sorting, one-line summaries and short replies. Read how Dusk's AI works.
Questions
- Do AI email apps read all my email?
- To sort or summarise it, the AI has to read it. The question is whether that happens on your device or on someone else's server.
- Which AI email app is the most private?
- Apps that run the AI on your own device. Dusk uses only Apple's on-device model. Apple Mail uses Apple Intelligence, on your Mac or Apple's Private Cloud Compute.
- Does Spark send my email to OpenAI?
- Spark says its AI features use Azure OpenAI and that email content is shared only to provide those features.
Fast, private email for $49 once
Pre-orders are open at the launch price. One payment covers the Mac app and the AI, and the iPhone app when it arrives.
Pre-order Dusk