Security and your data
Sujuu keeps your work on your computer, not on ours. We have no Sujuu cloud and no Sujuu account, so there is no copy of your mail, calendar, contacts or notes for us to lose. Here is how the app protects what it keeps.
1. Where your data lives
Everything you keep in Sujuu (mail it has downloaded, events, contacts, tasks, notes, projects and the files it has saved from mail) is stored on your computer, in your Windows user profile. Your mail stays with your mail provider as well, as it does now. We never receive any of it.
2. Encryption and keys
- An encrypted database. Sujuu's databases are encrypted with a random 256-bit key (SQLCipher). Files saved from mail are encrypted separately (AES-256-GCM).
- The key is protected by Windows. The database key is sealed with Windows' own data protection for your user account, so another Windows user, or someone who copies the files to another computer, can't open them. If Windows can't offer that protection, Sujuu refuses to store the key rather than store it weakly.
- A recovery key that only you have. When you set Sujuu up, it shows a recovery key once and asks you to save it. We never see it and Sujuu never stores it. Making a new one later asks for Windows Hello (your PIN, fingerprint or face) first.
- New keys when you want them. From Settings you can change the keys: Sujuu re-encrypts every database and backup with a new key at the next start, in a way that survives a crash part-way.
Because we hold no copy of your data or your keys, we can't recover it for you. If you lose both your computer and your recovery key, the data on that computer can't be opened. Keep the recovery key somewhere safe and apart from the computer.
3. Your accounts and passwords
Sujuu connects straight from your computer to your mail provider (IMAP and SMTP) and to your calendar and contacts (CalDAV and CardDAV, and calendar links). Nothing passes through a server of ours. The passwords and app passwords you give it are sealed with the same Windows protection as the database key, are never shown again, are never sent to us, and are left out of every backup.
To find your mail server settings, Sujuu asks your mail provider's own domain. It never sends your address to a lookup service.
4. Backups and moving computers
- Sujuu backs up daily, just before an update installs, and whenever you choose Back up now. Backups stay on your computer and stay encrypted.
- Saved passwords are removed from every backup, and the copy is rewritten so no trace of them is left in it.
- To move to a new computer, Sujuu makes an export locked with a passphrase you choose.
5. Keeping two computers in step
If you use Sujuu on two computers, they exchange changes through a private Sujuu Sync folder in your own mail account. Each batch is encrypted (AES-256-GCM) on your computer before it is uploaded, with a key your computers share when you pair them. Your mail provider stores only the encrypted batches, and we never see them.
6. What the app connects to
- Only what you set up. Your mail, calendar and contacts accounts, the calendar link you subscribe to, and our update check (section 7). Sujuu's window itself can't reach the internet; every connection goes through checks in the app.
- No analytics, no crash reports, no AI. The app sends no usage data and no error reports, and sends nothing to an AI service.
- Remote images are blocked. Pictures loaded from the web, which senders use to see when you open a message, stay blocked until you choose to show them.
- Careful unsubscribing. When you unsubscribe, Sujuu asks you first, uses only secure (https) links, sends no cookies, and won't connect to addresses inside your own network.
7. Updates
The installer and every update are signed by VitaImaging, LLC. Sujuu checks for updates on GitHub, where our releases are published, downloads them in the background, checks each file's fingerprint, and refuses one that isn't signed by us. It installs only when you choose Restart to update, and takes a backup first.
8. This website
- The site is served only over HTTPS, with strict security headers. Its scripts, styles and fonts all come from this site; it loads nothing from other companies and runs no trackers.
- The sign-up form sends your address to our own inbox and nowhere else. To limit abuse, it keeps only a scrambled, keyed form of your network address, and clears it once it's a day old. See Privacy.
9. Reporting a problem
If you think you've found a security problem in Sujuu or this website, please write to [email protected] with "Security" in the subject. We'll reply as soon as we can, keep you posted while we fix it, and credit you if you'd like. Please give us a fair chance to fix it before telling others, and don't access other people's data while testing.
No software is perfectly secure. We keep Sujuu's components up to date, review each release for security problems, and watch for known vulnerabilities in what it depends on.