Citus is Latin for fast

Fast, private email that stays yours

A free, open-source mail client for Linux, Windows and Android. No subscriptions, no ads, no tracking, and no server of ours: your mail goes only between your device and your mail provider.

Download Source on GitHub

Works with Gmail, Outlook and any IMAP/SMTP provider.

Citusmail on the desktop: the Smart Inbox with Pinned, Verification, Important and General sections

Citusmail on a phone: the same Smart Inbox

What sets it apart

Your subscriptions, found in your mail

Paid subscriptions send a receipt every time they charge you, but they're easy to forget. Citusmail reads your receipts, bills and renewal emails on your device and lists every subscription it finds:

what you spend a year, a month and a day, and how it splits between your subscriptions;
each one's price, how often it charges and the next charge;
every past receipt, opening right in place, and when the price went up;
phone, broadband and utility bills too, with their average when they vary.

The Subscriptions page: what you spend a year, a month and a day, and how it splits between subscriptions

Codes in the list

One-time codes, sign-in links and password resets get their own section, and the code shows without opening the email. Copy it with a tap.

Phishing checks that read the message

Besides forged senders and lookalike links, Citusmail warns when an outsider writes in the name of your own school or company, or a big brand, especially with hidden recipients or a form "portal".

No server of ours

Everything runs on your device. There is no Citusmail account, cloud or tracking, and your mail is stored encrypted.

A scam from a real, verified address, with a red warning that lists why it's suspicious

Everything you need from a mail app

Smart Inbox. Mail sorted on your device into Pinned, Verification, Important, General, Notifications and Newsletters.
Several accounts in one inbox. Any IMAP/SMTP provider, Gmail and Outlook / Microsoft 365, with their own sign-in.
Privacy by default. Images and trackers blocked, read receipts never sent, tracking removed from links, one-tap unsubscribe, and blocking senders.
Writing mail. Drafts, replies, undo send, custom folders and rules.
Every message, whole. Save it as an .eml file, see its original headers and source, or forward it as an attachment.
Encrypted everywhere. Encrypted storage, passwords in the system keychain, end-to-end encrypted sync of settings between your devices, and an app lock with PIN or fingerprint.

Reading on a phone: the warning, Reply and Forward, and the message actions at the bottom

Writing on a phone: To, Subject and the message, with Send at the bottom

Settings on a phone: notifications, how far back mail is kept, app lock

On phones, the menu, search, New message and Send sit at the bottom of the screen, within reach of one thumb.

Download

Version 0.4.5 · Free, with no account to create.

Android APK for your phone or tablet Linux · .deb Ubuntu, Debian, Mint and more Linux · Flatpak Any Linux with Flatpak Windows Installer for Windows 10 and 11

All files, checksums and release notes are on the releases page.

Your privacy

Citusmail has no account with us and no server of ours. We don't collect, receive, store, sell or share your data, and there's no analytics, crash reporting or advertising. Your mail, contacts and settings stay on your device, encrypted, and travel only between your device and your own mail provider, plus optional services you turn on yourself.

Read the privacy policy · Terms of service