Citusmail Privacy Policy
Effective date: 1 November 2026
Citusmail is an email app published by Fluminaris. This policy explains what the app does with your information. Questions or requests: kungchihchia@gmail.com, or an issue at https://github.com/pawtaetoe/Citusmail/issues.
In short
- Citusmail has no account with us and no server of ours. We do not collect, receive, store, sell or share any of your data.
- No analytics, no crash reporting, no advertising, no advertising ID, no tracking.
- Your mail, contacts and settings stay on your device, encrypted, and travel only between your device and the services you use: your own mail provider, and optional services you turn on yourself.
The data the app handles
To work as an email app, Citusmail handles on your device:
| Data | Why | Where it goes |
|---|---|---|
| Your email address, mail server settings, and password or sign-in token | To connect to your mail account | Only to your own mail provider (and its sign-in service, see below). Passwords and tokens are kept in your device's secure keychain |
| Your email messages, attachments, contacts and folders | To show, search, sort and send your mail | Downloaded from and sent through your own mail provider; stored encrypted on the device |
| App settings, blocked senders, folder rules | To remember your choices | On the device; optionally synced between your own devices, end-to-end encrypted (see below) |
None of this is sent to Fluminaris or to any third party other than the services listed in the next section.
Features that understand your mail, such as sorting, finding verification codes, phishing checks and the list of your paid subscriptions (found in receipts and renewal emails), run entirely on the device.
Services the app connects to
| Service | When | What is sent |
|---|---|---|
| Your mail provider (IMAP, SMTP) | Always, to read and send mail | Your login and your mail, over encrypted connections (TLS) |
| Google sign-in (Gmail) | Only if you add a Gmail account with "Sign in with Google" | Sign-in happens on Google's page in your browser; the app then receives a token to access your mail. Your password never passes through the app |
| Microsoft sign-in (Outlook, Microsoft 365) | Only if you add such an account | As for Google: sign-in on Microsoft's page, then a token for your mail |
| Your provider's setup information, your DNS resolver | When you add an account | Your email domain, to find your mail server settings |
| Mozilla's mail server database | Only if you allow it during setup | Your email domain (never your full address) |
| Your mail server's rules service (ManageSieve) | Only if you turn on "Rules on the mail server" (Settings > Advanced) | Your blocked senders and folder rules, so your server can sort mail |
| Google Safe Browsing | Only if you turn on "Check links with Google Safe Browsing" (Settings > Advanced) | Lists of dangerous sites are downloaded; to confirm a match, only a 4-byte part of a link's fingerprint is sent, never the link itself |
| VirusTotal | Only if you turn it on with your own API key (Settings > Advanced), and only when you tap "Check with VirusTotal" | A file's SHA-256 fingerprint (the file is never uploaded) or a link's address |
| Newsletter senders | Only when you tap Unsubscribe and confirm | The unsubscribe request the newsletter asked for |
| Images and links in an email | Only when you choose to load images or open a link | A request for the image or page, without cookies; like any connection, it shows your IP address |
Each of these services handles data under its own privacy policy.
Google user data
When you sign in with Google, Citusmail asks for access to your Gmail mailbox (IMAP and SMTP) so it can show and send your mail. This data is used only to provide the app's email features to you, on your device. It is not transferred to Fluminaris or to anyone else, not used for advertising, and not read by people.
Citusmail's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.
Sync between your devices (optional)
Off until you turn it on. Then your blocked senders, unsubscribes, folder rules and image choices are kept the same on your devices. They travel through a folder in your own mail account, never through a server of ours, and are end-to-end encrypted with a code only your devices hold.
Android permissions
| Permission | Why |
|---|---|
| Internet, network state | To connect to your mail provider |
| Notifications | To tell you about new mail (sender and subject only; on the lock screen only that there is new mail) |
| Foreground service, start at boot | To check for new mail in the background, or keep a live connection if you turn on "Instant mail" |
| Fingerprint or face unlock | Only if you turn on the app lock; checked by Android, the app only learns "yes" or "no" |
The app does not use your location, camera, microphone, contacts list or advertising ID.
Security
Connections to mail servers are encrypted (TLS). Mail and settings on the device are stored in an encrypted database whose key is kept in the device's secure keychain. Passwords and sign-in tokens are kept only in that keychain. Images and trackers in emails are blocked unless you load them, and the app checks messages for signs of phishing on the device.
Keeping and deleting your data
Your data stays on your device for as long as the account is in the app. Removing an account from the app deletes its mail and settings from the device; uninstalling the app deletes everything it stored. Mail on your mail provider's servers is managed by your provider and is not affected, except by actions you take in the app (such as deleting a message).
Because Fluminaris holds no data about you, there is nothing for us to delete; you can still contact us with any question.
Children
Citusmail is not directed at children under 13 and does not knowingly collect data from anyone.
Terms of service
Using Citusmail is also covered by the Terms of Service.
Changes to this policy
If this policy changes, the new version will be published at this address with a new effective date.