Privacy Policy

Last updated: 26 August 2026

ThreadMail is a desktop email client. It is written and published by Loan Guilbaud, an independent developer. This page explains what happens to your data when you use it.

The short version

ThreadMail runs on your own computer and connects straight to your mail provider over IMAP and SMTP. There is no ThreadMail server, no ThreadMail account, and no place for your email to go except your machine and your provider. Nobody but you can read it, including the developer.

Who handles your data

You do. The developer operates no mail server, no proxy and no backend that touches your email. Your messages, attachments and credentials never pass through any machine run by ThreadMail. They travel between your computer and the mail servers you configured — for a Gmail account, that means Google's own IMAP and SMTP servers.

Google user data

If you sign in with Google, ThreadMail asks for one OAuth scope: https://mail.google.com/. That scope lets the app do the following, on your computer, at your request:

Read your email messages, including their bodies, headers and attachments, so it can show them to you as conversations.
Read message metadata — senders, recipients, subjects, dates, flags and folder names — so it can group conversations, sort them and show unread counts.
Change message state: mark as read or unread, move, archive and delete, when you ask for it.
Send mail on your behalf when you write a reply or a new message.

Why the scope is this broad

ThreadMail talks to Gmail as a normal mail client, over IMAP and SMTP, authenticating with XOAUTH2. Google only accepts https://mail.google.com/ for that. The narrower Gmail API scopes (such as gmail.readonly or gmail.modify) cannot authenticate an IMAP or SMTP session at all, so there is no smaller scope that would work. The app requests nothing else — no profile, contacts, calendar or drive access.

Where it is stored and for how long

Your mail is cached in a SQLite database in ThreadMail's data folder on your own computer, so the app opens instantly and works offline. That folder is the standard per-user application data directory for your operating system (for example %APPDATA% on Windows, ~/Library/Application Support on macOS, ~/.local/share on Linux). The cache is kept for as long as you keep the app installed, minus whatever the app's own retention settings prune. It is a cache: deleting it loses nothing that is not still on the server.
Your Google refresh token is stored in your operating system's keyring (Windows Credential Manager, macOS Keychain, or the Secret Service on Linux). It is never written to a configuration file or to any other disk location, and it never leaves your machine except to go back to Google.
Nothing is uploaded anywhere. There is no backup, no sync service and no remote copy.

How to delete it

Remove the account in ThreadMail to drop its stored credentials.
Delete ThreadMail's data folder to remove the cached mail. Uninstalling the app and deleting that folder removes everything ThreadMail kept.
Revoke ThreadMail's access to your Google account, as described below. Your mail itself stays with Google — ThreadMail never had the only copy of anything.

How to revoke access

In ThreadMail, open the account's settings and choose to revoke access. The app sends a revocation request to Google, which invalidates the whole grant server-side, not just the local copy of the token. You can also revoke it yourself at any time from your Google account's third-party access page. Either way, ThreadMail can no longer reach your mailbox.

Limited Use disclosure

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

Because ThreadMail runs entirely on your computer and the developer operates no servers, Google user data obtained through these scopes is:

never transferred to any third party;
never used for advertising, marketing or any other purpose than running the features you asked for;
never sold;
never used to train any machine-learning or AI model;
never read by humans, including the developer.

Requests ThreadMail makes to the developer's servers

One, and it carries nothing about you or your mail:

Update check. The app periodically fetches latest.json from the site's Firebase Hosting origin (threadmail-1.web.app) to see whether a newer version exists. It is a plain file download, the same for everyone, with no identifier attached.

The installers and app updates themselves are downloaded from GitHub, where they are published as release files; those downloads are handled by GitHub under its own privacy statement, and this site learns nothing about them.

This website itself sets no cookies, loads no fonts, scripts or images from other domains, and runs no analytics.

Security

Connections to your mail provider use TLS. Credentials live in your operating system's keyring rather than in a file. The OAuth sign-in uses the Authorization Code flow with PKCE and a loopback redirect, which is the flow Google recommends for desktop apps. Beyond that, the security of your mail depends on your own machine and your provider's account protection.

Children

ThreadMail is not aimed at children under 13 and collects no data from anyone, so it holds no children's data.

Changes to this policy

If how the app handles data changes, this page changes with it and the date at the top is updated. Since the app is downloaded rather than served, an older installed version keeps behaving the way it did when you installed it.

Contact

Questions about this policy: [email protected].