Sterna Mail
Private email client for JMAP and IMAP/SMTP. No Google services, no tracking.
Version: 1.4.9
Added: 10-07-2026
Updated: 11-08-2026
Added: 10-07-2026
Updated: 11-08-2026
Sterna Mail is a private, modern email client for Android, built for JMAP, the faster successor to IMAP, with full support for classic IMAP/SMTP too. You pick the protocol when you add an account, so Sterna Mail works with JMAP servers like Stalwart as well as any standard mail provider.
It is private by default, pleasant to use, and fully free software (GPLv3). No tracking, no ads, no analytics, and no Google services required.
Reading and organising:
* Unified inbox across multiple accounts (JMAP and/or IMAP/SMTP), fully offline with a local cache
* Multiple JMAP accounts under a single login (delegated, shared or team mailboxes), each with its own folders, notifications and Sent copies
* Conversation threading, nested folders, configurable swipe actions, stars, archive and delete with undo
* Multi-select bulk actions, snooze, report spam, sort and unread-only filter
* Search as you type, combining instant local results with server-side search, plus filters for sender, subject, attachments and date
* Calendar invitations preview as an event card and go into your calendar app in one tap
Writing and sending:
* Compose with recipient autocomplete, multiple identities each with its own signature, attachments and drafts
* Replies come from the address the message was sent to, with that identity's signature
* Undo send, schedule send, and reminders for a forgotten attachment or a large recipient list
* Opens mailto: links from any app or browser, prefilled
Accounts, notifications and encryption:
* Add an account with just your email and password (autodiscovery), password-free OAuth 2.0 sign-in, or manual IMAP/SMTP setup with provider presets
* Push notifications for new mail with no Google and no FCM, over JMAP EventSource, IMAP IDLE or UnifiedPush, grouped per account and with quiet hours
* OpenPGP encryption through OpenKeychain, on both JMAP and IMAP/SMTP. Decrypted content is never written to disk; an attachment you open is written to the app's own storage until the cache is cleared
* Remote images and tracking pixels blocked by default, and tracking parameters can be stripped from links before they open
* Credentials encrypted with the Android KeyStore, app lock with biometrics or a PIN
Server features and polish:
* Server-side vacation responder, Sieve filter rules, and mailbox quota display
* Material 3 interface with its own light and dark themes, optional Material You, and adjustable message text size
* Available in nine languages: English, French, German, Spanish, Italian, Portuguese, Dutch, Polish and Russian
* Screen-reader friendly, with settings export and import
Sterna Mail is open source, and its release builds are reproducible: F-Droid checks that the app it distributes is byte for byte the one built from the published source. The code can be read, audited, and improved by anyone.
It is private by default, pleasant to use, and fully free software (GPLv3). No tracking, no ads, no analytics, and no Google services required.
Reading and organising:
* Unified inbox across multiple accounts (JMAP and/or IMAP/SMTP), fully offline with a local cache
* Multiple JMAP accounts under a single login (delegated, shared or team mailboxes), each with its own folders, notifications and Sent copies
* Conversation threading, nested folders, configurable swipe actions, stars, archive and delete with undo
* Multi-select bulk actions, snooze, report spam, sort and unread-only filter
* Search as you type, combining instant local results with server-side search, plus filters for sender, subject, attachments and date
* Calendar invitations preview as an event card and go into your calendar app in one tap
Writing and sending:
* Compose with recipient autocomplete, multiple identities each with its own signature, attachments and drafts
* Replies come from the address the message was sent to, with that identity's signature
* Undo send, schedule send, and reminders for a forgotten attachment or a large recipient list
* Opens mailto: links from any app or browser, prefilled
Accounts, notifications and encryption:
* Add an account with just your email and password (autodiscovery), password-free OAuth 2.0 sign-in, or manual IMAP/SMTP setup with provider presets
* Push notifications for new mail with no Google and no FCM, over JMAP EventSource, IMAP IDLE or UnifiedPush, grouped per account and with quiet hours
* OpenPGP encryption through OpenKeychain, on both JMAP and IMAP/SMTP. Decrypted content is never written to disk; an attachment you open is written to the app's own storage until the cache is cleared
* Remote images and tracking pixels blocked by default, and tracking parameters can be stripped from links before they open
* Credentials encrypted with the Android KeyStore, app lock with biometrics or a PIN
Server features and polish:
* Server-side vacation responder, Sieve filter rules, and mailbox quota display
* Material 3 interface with its own light and dark themes, optional Material You, and adjustable message text size
* Available in nine languages: English, French, German, Spanish, Italian, Portuguese, Dutch, Polish and Russian
* Screen-reader friendly, with settings export and import
Sterna Mail is open source, and its release builds are reproducible: F-Droid checks that the app it distributes is byte for byte the one built from the published source. The code can be read, audited, and improved by anyone.