Katna Privacy Policy

Katna is a free, open-source personal project by Mozammel, published under the GNU General Public License. Its source code, including everything this page describes, is public at github.com/QuakeString/katna, so anyone can check it.

For anything about your information, write to katnamail@gmail.com.

Your mail, calendars, contacts, tasks, notes, attachments, search index, settings and drafts are stored on your computer and nowhere else. On Linux they live under ~/.local/share/katna, ~/.config/katna and ~/.cache/katna; on Windows under %APPDATA%\Katna and %LOCALAPPDATA%\Katna.

Passwords and sign-in tokens are kept in your system's password store (KWallet, GNOME Keyring, KeePassXC or Windows Credential Manager), never in a file.

Spell checking, grammar checking, writing suggestions and language detection all run on your computer. Writing suggestions learn from your sent mail without it leaving your computer.

If you turn on Settings > MCP server, AI assistants running on your own computer can search and read your mail through katnactl, and save drafts if you allow it. This is off until you turn it on, never sends mail, and nothing leaves your computer unless the assistant you use sends it somewhere.

Katna connects directly from your computer to the mail, calendar and contacts services you add, such as Gmail, Outlook, Zoho, Yahoo or your own server. What those services do with your data is covered by their own privacy policies. Katna has no server in between.

When you add an account, Katna looks up its settings. It asks your own mail provider with your address, and asks Mozilla's Thunderbird settings database with only the domain (the part after the @).

When you sign in with Google, Microsoft or Zoho, Katna asks for access to mail, calendars, contacts and tasks so it can sync them. With Google and Microsoft it also asks for Drive or OneDrive, so that attachments too large to email can be sent as shared links. Katna only shares a file with the people you are sending it to, and asks you first before making a link that anyone can open.

When you sign in with a Google account, Katna uses the Google data it is given access to (Gmail, Calendar, Contacts, Tasks, Drive and Meet) only to show, search, sync and send it for you inside Katna, and to provide the features you choose on this page.

Katna'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.

Google data is not sold, not used for advertising, and not read by people, except with your explicit permission for a specific message (for example when you send us one in a bug report), when needed for security, or when the law requires it. Katna does not use Google data to develop, improve or train generalized AI or machine learning models.

Google data leaves your computer only when you use a feature that needs it: Katna AI or translation (the text you ask about goes to Katna Server, as described below), read tracking (links in mail you send), and Drive for large attachments. You can remove Katna's access at any time from your Google Account's security settings, at myaccount.google.com/permissions.

A few things happen without you clicking anything:

A Katna account is optional. You need one for read tracking, translation and Katna AI; everything else works without it, and Katna doesn't contact Katna Server at all while you are signed out.

For an account we store your email address, a one-way hash of your password, and when the account was created and confirmed. For each computer you sign in on we store its name (your computer's hostname), when it signed in and when it was last seen. Sign-in codes reach you by email through Zoho's mail service.

Unconfirmed accounts are deleted after seven days. You can delete your account at any time, which deletes its computers, tracking data and AI usage with it.

When you are signed in to a Katna account, Katna can tell you when a recipient opens your mail or clicks a link in it. It is on for new mail by default and can be turned off for any message before you send it. Each recipient's copy carries a small image and links that point at Katna Server, with a random number that only your computer can match to a person.

Katna Server stores the random number, the time of each open or click, which link was clicked and its address, and whether the open looked like a person, Apple Mail's privacy proxy or a security scanner. It does not receive or store the subject, the recipients or the text of your mail. A recipient's IP address and browser details are used for that check at the moment of the open and are not stored. Tracking data is deleted after 180 days.

Katna can also ask the recipient's mail app for a read receipt and your mail server for a delivery report. Both are standard email features that go through the mail servers, not through Katna Server.

Katna's AI features (Rephrase, Summarize, Write a reply, subject ideas) only send text when you ask for them. Autocomplete is off until you turn it on; while it is on, it sends the paragraph you are writing when you pause. You can turn AI off entirely in Settings, and encrypted mail is never sent without asking you each time.

For a rephrase, Katna sends the selected text and your instruction. For a summary or a reply, it sends the conversation's latest messages with the senders' names, the times and the text, without quotes, signatures or email addresses.

When you click Translate, or choose a language to always translate, the plain text of that mail goes to Katna Server and is translated by LibreTranslate running on the same server. Headers, addresses and attachments are not sent, the text is not logged, and encrypted mail is never offered for translation. It needs a Katna account.

If Katna crashes, it saves a report on your computer, with your name, computer name, email addresses and web addresses removed. Reports are only sent if you agree when Katna asks, and you can change your mind in Settings.

Sent reports go to Sentry, in its European Union data centre, without your IP address or any account details, and are kept for 90 days.

Katna can send anonymous usage statistics once a week, but only if you turn this on in Settings. Nothing is recorded while it is off, and turning it off deletes what was recorded.

A weekly report says which of a fixed list of features you used that week (yes or no for each, never how or on what), Katna's version, the kind of Linux or Windows, the desktop and screen scale, and roughly how many accounts you have (0, 1, 2–3 or 4+). It carries a random number that is replaced every 90 days, and nothing that identifies you. Reports go to Sentry in the European Union, like crash reports.

Katna has no advertising and no tracking of what you do in the app beyond the opt-in statistics above. We do not sell or share your information with anyone, and we never read your mail.

Katna Server runs at server.katna.invenia.in on a server we operate. Besides your mail providers and the AI service you choose, the services described above are GitHub (updates), Google Gemini (Katna AI), Zoho (sign-in codes) and Sentry (crash reports and usage statistics, only if you agree). Some of them process data outside India.

You can ask what information we hold about you, ask us to correct or delete it, or withdraw a consent you gave, under India's Digital Personal Data Protection Act and, where it applies to you, the GDPR. Most of it you can do yourself: delete your Katna account from Settings, turn tracking, AI, sender logos, crash reports and usage statistics off, or remove Katna and its folders from your computer.

Katna is not aimed at children under 18 and we do not knowingly hold accounts for them.

If Katna starts handling information differently we will update this page and the date at the top of it, and note material changes in Katna's What's new.