Privacy policy

Last updated 17 October 2026

This policy explains what the Terndesk desktop email app and this website do with your information. "We" means Terndesk, the publisher of the app. In short: no Terndesk server ever receives your mail or your Google data. The app runs on your computer, talks directly to Google and to the mail servers you add, and keeps what it downloads on your computer. We never receive your email, your calendar, your contacts or your passwords.

Summary

Terndesk reads your Gmail, Google Calendar and Google Contacts only with your permission, through Google's official APIs, to show them to you and to carry out what you do in the app.
Everything it downloads is stored on your own computer. Sign-ins and passwords are stored in your operating system's secure credential store.
We have no servers that store or relay your mail or your Google data, and the app contains no analytics, advertising, tracking or crash reporting.
The only thing the app ever sends us is your licence key and an identifier for your computer (with its name), when you activate or remove a licence.
AI features run on your computer by default. If you choose a cloud AI provider, text from your email goes directly from your computer to that provider, under your own account, and only after you tick a consent box.
We don't sell your data, use it for advertising, or use it to train AI models.

Google user data the app accesses

When you choose Sign in with Google, your web browser opens Google's own sign-in and consent page. You see the permissions listed below and decide whether to grant them. Terndesk requests these permissions, and uses each one only for the purpose given. All of this Google data stays on your computer.

openid, email, profile: What it allows: Your Google account's email address, name and profile picture.; Why Terndesk needs it: To know which Google account you signed in with, show it in the app, and use your address when you send mail and answer invitations.
https://www.googleapis.com/auth/gmail.modify: What it allows: Read, compose, send and organise your Gmail messages, drafts and labels. It does not allow permanent deletion.; Why Terndesk needs it: To bring your mail into the app so you can read and search it, to carry out what you do in the app (such as archive, mark read, star, label, snooze, or move to trash or spam) in Gmail, to send mail and save drafts, to let you choose your "From" address and signature, and, if you turn on settings backup, to keep a copy of your app settings in your own mailbox.
https://www.googleapis.com/auth/gmail.settings.basic: What it allows: Read and change your basic Gmail settings.; Why Terndesk needs it: To show and change your out-of-office auto-reply from the app. If you choose to run your rules as Gmail filters, also to create those filters, to remove filters the app created, and to read your existing filters so you can import them as rules.
https://www.googleapis.com/auth/calendar.events: What it allows: View and edit events on all your calendars.; Why Terndesk needs it: To show your agenda and the events behind invitations, let you answer invitations, create events (with a Google Meet link if you ask for one), edit or delete events you choose, and suggest free times by checking when you and the people you're scheduling with are busy.
https://www.googleapis.com/auth/calendar.calendarlist.readonly: What it allows: See the list of calendars you're subscribed to.; Why Terndesk needs it: To show your calendars by name and colour and let you choose which ones appear in the app.
https://www.googleapis.com/auth/contacts.readonly: What it allows: See your Google Contacts.; Why Terndesk needs it: To suggest names and email addresses while you type a recipient. Only names and email addresses are read.

These requests go from your computer directly to Google over encrypted connections.

How the app uses your data

Terndesk uses your data only to provide the features you see in the app: showing, searching and organising your mail; writing, sending and scheduling messages; drafts, snoozes and reminders; your calendar and invitations; recipient suggestions; and, if you turn them on, AI features (see AI features). All of this happens on your computer.

Where your data is stored

Mail, calendar and contacts, together with your drafts, messages waiting to be sent and your settings, are stored in the app's data folder on your computer, which only your user account can read.
Sign-ins and passwords (your Google sign-in, the password or sign-in of any other mail account, and a cloud AI key if you enter one) are stored in your operating system's secure credential store.
Nothing from your mailbox is stored on any server operated by us. Your mail also stays in your Google account as usual; Terndesk works on a copy.

We don't receive your mail or your Google data, so we can't share or sell it. The app itself sends data only to these places, and only to do what you ask:

Google, to sync your mail, calendar and contacts and to carry out your actions (for example, sending a message or accepting an invitation). When you look for a free time, the email addresses of the people you're scheduling with are sent to Google Calendar to ask when they're busy.
The mail servers of other accounts you add, using the server settings and password you provide. While you add such an account, the app may look up its settings from your mail provider's own published settings; only if you tick the option does it also ask Mozilla's public database of mail settings, which receives your mail domain (not your address). If you sign in to a Microsoft or Yahoo account, that sign-in happens with Microsoft or Yahoo in your browser.
Our licence service, only when you activate or remove a licence: it receives your licence key and an identifier for your computer, including the computer's name. Nothing from your mailbox or your Google account is sent.
A cloud AI provider, only if you choose one, as described below.
Senders' image servers, only if you allow it. Remote images in email are blocked by default. If you choose to load images for a sender (or for all mail), the app loads them from the servers that host them, which can tell that the message was opened and see your IP address, as they would in any email app.
Your web browser, when you click a link in an email or sign in: links open in your own browser, not inside the app.

Terndesk also includes optional tools that let programs you run on your own computer (for example, an AI assistant you have set up yourself) read the mail the app has stored. These tools never connect to the network themselves. If you connect them to an AI assistant, what that assistant does with the mail it reads is governed by that assistant's own terms.

AI features

AI features (such as summaries, drafting, suggested replies, search in plain words, answers about your mail, and optional automatic sorting and reply drafts for new mail) are optional. You choose where they run in Settings:

On your computer (the default): requests go to a local AI model running on your own computer. Nothing leaves your device.
A cloud AI provider you choose, with your own API key, or through a provider's tool you have installed and signed in to yourself. These are used only after you select the provider and tick a box confirming that email text will be sent to it.

When you use a cloud provider, the text needed for the task you asked for (for example, the conversation you want summarised) is sent directly from your computer to that provider, under your own account with them. It does not pass through us. That provider's handling of the data is governed by your agreement with it, so please read its terms and privacy policy before turning it on. If you turn on automatic sorting or automatic reply drafts, the app sends new mail to the provider you chose in the background, without asking each time. You can switch AI back to your computer or off at any time.

We never use your data, including Google user data, to develop, improve or train AI or machine-learning models.

Google API Services User Data Policy (Limited Use)

Terndesk's use and transfer to any other app of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements. In particular:

Google user data is used only to provide and improve the user-facing features of the app described above.
It is transferred to others only when needed to provide those features, with your consent (for example, to the cloud AI provider you chose), for security purposes, or to comply with applicable law. Because the app runs entirely on your computer, it is never transferred to us.
It is never used for advertising, including personalised, retargeted or interest-based advertising.
It is never sold, and never transferred to data brokers or information resellers.
No person reads it. We have no access to it; it exists only on your computer and in your Google account.
It is never used to develop, improve or train generalised or non-personalised AI or machine-learning models.

Security

Google sign-in happens on Google's own page in your browser; the app never sees your Google password.
All connections to Google and to mail servers are encrypted, with certificate checks.
Scripts in email never run, and remote content stays blocked until you allow it.
The app has no telemetry, so there is no stream of data about you to protect or leak.

Your data is as safe as your computer: anyone who can sign in to your user account can open the app and its data, so use a password and disk encryption.

Keeping and deleting your data

The app keeps your data on your computer until you remove it. You can:

Remove an account in the app's Settings. This deletes that account's mail, calendar events, contacts, drafts and other synced data from your computer, and its sign-in or password from your credential store. For a Google account, the app then also asks Google to revoke its access.
Revoke access at any time at myaccount.google.com/permissions. After that the app can no longer reach your Google account.
Delete everything: quit the app, uninstall it, and delete its data, which is kept in folders named dev.tern.mail in your user account's application data and cache folders, and any entries named dev.tern.mail in your credential store.

Removing data from Terndesk doesn't delete anything from your Google account; your mail stays in Gmail. Because we hold none of your mail or Google data, there is nothing of it for us to delete on our side.

Buying a licence

Terndesk is paid software, but licence keys aren't on sale yet. Before they are, this policy will be updated to say what buying one involves, for example the email address a key is sent to and who processes the payment. How the app handles your mail doesn't change.

This website

This website has no analytics, sets no cookies and loads nothing from other sites. It remembers your light or dark theme choice in your browser's local storage. Like any website, the hosting provider that serves it processes your IP address and request details to deliver the pages and protect against abuse.

Children

Terndesk is not directed at children under 13 (or the minimum age for a Google account where you live), and we don't knowingly collect information from them. As described above, the app sends us nothing but a licence key and an identifier for the computer, so we hold no mail or Google data about any user, child or adult.

Changes to this policy

If the app starts handling data differently, we'll update this policy and the date at the top before the change ships, and describe significant changes in the release notes. If a change would use data you've already shared in a new way, we'll ask for your consent in the app first.

Contact

Questions about this policy or your data: hello@terndesk.com. See also the terms of use.