Mail Deck 1

Privacy policy

Last updated: 2026-11-04

Mail Deck has no servers, no analytics and no tracking. Nothing it reads leaves your browser except the requests it sends to the mail services themselves: to Google for Gmail, and to each other mail service you turn on. If you turn on the AI assistant with your ChatGPT plan or your own key from an AI provider, the mail it works on also goes to that provider, as described below; with a model on your own computer, it stays there.

What it reads from Gmail

Other mail services

Yahoo Mail, AOL Mail, Proton Mail, Yandex Mail and Mail.ru are off until you turn one on in Settings → Other mail. Chrome then asks you to allow that service’s sites, listed below, one service at a time. Until you allow them, Mail Deck sends that service nothing. Turning a service off removes the permission again.

Each service is read the way its own web page reads it, with the session your browser already has on its site. Mail Deck never asks for, sees or stores your password, an app password or an OAuth token. As with Gmail, it reads the unread mail of the inbox (the sender, the subject, the time and, where the service gives one, a short snippet) and sends your actions, such as mark as read, archive, delete or report spam, back to the same service.

The interfaces of Yahoo Mail, AOL Mail, Yandex Mail and Mail.ru expect requests that come from their own web page. For each of these services you turn on, Mail Deck adds a Chrome rule (declarativeNetRequest, kept for the browser session) that sets the Origin and Referer headers to the service’s own address, only on Mail Deck’s own requests to that interface: mail.yahoo.com/ws/, mail.aol.com/ws/, mail.yandex.ru/web-api, mail.360.yandex.ru/web-api and e.mail.ru/api/. The rule matches only requests the extension itself sends in the background, never a request from a tab, and it does not read, block or change anything else. Turning the service off removes its rule. Proton Mail needs no such rule.

The page you are on

When you open the panel with its toolbar button or its keyboard shortcut, Chrome lets Mail Deck read the address of the tab you are on, for that tab only (the activeTab permission). Mail Deck takes the site’s domain from it and shows, at the top of the panel, the unread mail whose sender is that site, with a one-time code ready to copy. The comparison happens inside the panel. The address is not stored and is not sent anywhere. In the side panel this works only for tabs on which you used the toolbar button.

AI assistant

The AI assistant is off until you turn it on. Its buttons show in the panel from the start and, while it is off, only offer to turn it on (Settings → AI can hide them): nothing is sent to any provider before you choose one. Once on, it can:

The assistant never sends mail on its own. A draft goes only when you press Send (Gmail, with five seconds to undo, as described above); otherwise it opens in your mail service’s compose window, or is copied.

You choose where it runs:

Requests go from your browser straight to that provider; Mail Deck has no servers in between. Each request sends only what it needs, with the current date, time and time zone so that dates such as “tomorrow at 3” can be read:

The provider handles this data under its own terms, linked above.

Your API keys and the ChatGPT sign-in (its tokens, the app id OpenAI issued to this browser, an anonymous random id of this browser that OpenAI asks for, and your account’s email address) are kept only in this browser’s extension storage on your device (chrome.storage.local). They are never part of a settings backup or of Chrome sync, never shown in diagnostics, and sent only to their own provider. Disconnect removes them and Chrome’s access to the provider. A summary (its key points, what it asks of you, its dates and details, not the mail itself) is kept on your device for 7 days, at most 200 of them, so a mail opened again shows it at once; the assistant’s conversation is kept in session storage, in memory only, until the browser closes. How a mail was sorted (waiting for a reply, important or newsletter, and a few words why) is kept on your device for 30 days, so the same mail is not sent again.

Translation by Chrome’s own translator (Translate from … in an open message) runs on your computer and needs no assistant: Chrome may download a language pack from Google once, from your click, and nothing of the mail leaves your device.

The clipboard

When you turn on Settings → Notifications → Copy sign-in codes from notifications, Chrome asks you to let Mail Deck write to the clipboard (the optional clipboardWrite permission). Then a new mail’s notification that carries a one-time code has a Copy button: a click puts that code, found in the mail’s subject or preview, on your clipboard. Mail Deck never reads the clipboard, and nothing is sent anywhere. Turning the switch off gives the permission back.

Where it goes

To the mail services themselves: mail.google.com for Gmail, and the sites above for each other service you turn on. A service’s mail, addresses and tokens go only to that service. To the AI provider you chose, if you did, as described above. And to Google in two more cases:

Pictures and trackers. A Gmail message you open in the panel shows its pictures through Google’s image proxy, as Gmail does, unless you turn on “Ask before showing pictures in Gmail mail” (Settings → Panel → More options); then they wait for Show pictures. In a message of another service, pictures from the internet always wait for Show pictures. Before anything of a message loads, Mail Deck checks each of its pictures inside the extension: a picture that only reports that you opened the message (a known open-tracking pixel, or a hidden or one-pixel picture whose address could identify you) is never loaded, not even by Show pictures, and the panel says how many it kept out and whose. The list is built into Mail Deck: nothing is downloaded or sent to check a picture.

Sender warnings. For the message you open, the panel compares the sender’s name and address, and its Reply-To when Gmail shows one, with a list of well-known brands and domains built into Mail Deck, and says so when they do not match. This happens inside the panel; nothing is sent anywhere.

Unsubscribe. When you open a Gmail message, Mail Deck reads its header from mail.google.com (only the lines that say how to unsubscribe, the message id, Gmail’s own check of the sender’s signature and the addresses a reply would go to) to offer Unsubscribe. Nothing is sent until you choose Unsubscribe and confirm: then, as the sender’s header asks, Mail Deck either sends one request to the sender’s unsubscribe address, with no cookies and nothing about you but what that address already holds, or opens a pre-filled email in Gmail for you to send, or opens the sender’s page in a tab.

Mail Deck does not send your mail, addresses, cookies or settings to its author, or to anyone other than the services named above. It does not sell or share data, and it does not use your data for advertising or credit decisions.

What it stores

Your settings (including which mail services you turned on), the order of your inboxes, the reminders you set and the current unread counts are kept in the browser’s extension storage (chrome.storage) on your device. So that a message opens at once, the last messages you opened (or, in Gmail, pointed at), from any service, up to 3 MB, and Gmail’s answers to the panel’s searches, are kept in the session part of that storage: in memory only, never written to disk, and gone when the browser closes. An action you just took waits out its five-second Undo in the extension’s storage on your device, so that a browser closing meanwhile does not lose it. The same session storage holds what the other services need between checks: the tokens their pages hand out, which Proton session is which account, each service’s last answer, shown for up to 30 minutes when a check fails, and which listed message belongs to which mailbox. Reminders never reach Gmail or any other service. Removing the extension deletes all of it, except a settings copy you chose to keep in Chrome sync, which you can turn off in settings.

Contact

Questions or problems: open an issue at https://github.com/nord-express/mail-deck/issues.