Frequently asked questions.

Epistles Mail is a native, local-first email client that unifies Gmail, Microsoft 365, Fastmail, Proton Mail, and any IMAP account into a single inbox.

It ships on macOS, Linux, Windows, iOS, Android, and the web (May 2026). Every message is stored locally in SQLite for offline use. Account credentials sync between devices through a zero-knowledge Cloud Vault encrypted with AES-256-GCM under a key only you hold.

Epistles Mail speaks each provider's native protocol:

Gmail and Google Workspace use the Gmail API. Microsoft 365 and Exchange Online use the Outlook Web App (OWA) private API at outlook.office.com, not Microsoft Graph and not EWS. Fastmail and any compatible server use JMAP. Proton Mail uses Proton's own API with on-device OpenPGP and no Bridge. Anything else connects via IMAP and SMTP.

Epistles Mail ships on macOS, Linux, Windows, iOS, Android, and the web at app.epistles.com. Six platforms, all generally available as of May 2026.

The Linux and Windows desktop builds use Tauri 2 with native WebViews and ship as .deb, .rpm, AppImage, and signed NSIS installers. The mobile apps are bare React Native, not Expo. None of the desktop builds use Electron.

Epistles Mail is free for up to three connected email accounts, with no ads and no time limit.

Pro costs $35 per year for unlimited connected accounts and includes a 15-day free trial that does not require a credit card up front. There is one tier above free; there are no add-ons, no upsells, and no usage-based billing.

Yes. Epistles Mail talks to Proton's own API directly and decrypts messages on-device with OpenPGP. No Proton Bridge or localhost daemon is required, on any platform.

The Proton mailbox passphrase and private OpenPGP keys live in the operating system keychain and are deliberately carved out of the Cloud Vault. Epistles Mail is the first shipping multi-platform third-party email client to support Proton Mail without Bridge.

As of May 2026, yes. Proton's official desktop app is built on Bridge, which runs a local IMAP/SMTP daemon. Third-party clients on Linux and Windows historically required Bridge to talk to Proton at all.

Epistles Mail talks to Proton's own API directly and decrypts on-device with OpenPGP, so no Bridge is needed on any of the six supported platforms. The Proton private keys never leave the device's operating system keychain.

Epistles Mail is the closest spiritual successor to Newton Mail. Both are unified-inbox clients that emphasize a quiet, opinionated UI over feature sprawl, with cross-device sync and read receipts.

Epistles supports more providers than Newton ever did (adding Proton Mail and any IMAP server), runs on six platforms (Mac, Linux, Windows, iOS, Android, web), is local-first, and uses a zero-knowledge Cloud Vault. Pricing is $35/year, less than Newton's final $50.

Yes. Epistles Mail is local-first. Every message, attachment, calendar event, and contact is stored on-device in SQLite, and the full-text search index runs locally.

Reading, searching, drafting, archiving, snoozing, flagging, and triaging all work with no network connection. Outbound actions (sends, moves, label changes) queue locally and replay to the provider when the device reconnects. The app is fully usable on a flight or in a tunnel.

No. Epistles Mail is proprietary closed-source software.

The trust mechanisms it offers instead are: zero analytics SDKs, no third-party crash reporter, AES-256-GCM client-side encryption of the Cloud Vault under a key derived from your password, a published subprocessor list, and native protocols rather than a server-side proxy.

If source-availability is a hard requirement, Thunderbird is a strong open-source alternative.

No. Epistles Mail ships with no analytics SDK, no third-party crash reporter, and no usage metrics.

The only network calls the app makes to Epistles servers are functional: Cloud Vault sync (ciphertext only), push registration, server-mediated OAuth refresh, optional image proxy, and opt-in outbound link tracking. Diagnostic logs stay on the device until you choose to export a bundle.

Both are multi-account, privacy-respecting clients. Thunderbird talks to most providers via IMAP; Epistles uses each provider's native protocol (Gmail API, OWA for Microsoft 365, JMAP for Fastmail, Proton API for Proton), so labels, categories, and threading are not flattened.

Thunderbird is open source and donation-supported. Epistles is closed source and $35/year. Epistles ships iOS, Android, and a web app today; Thunderbird's iOS app is still in development.

Yes. A native watchOS 10+ app paired to the iPhone build, with full triage (archive, snooze, voice or template reply, "Reply & Done", pin, forward to a contact) and an agenda glance with RSVP. WidgetKit complications ship in rectangular, circular, inline, and corner styles, showing unread count and first sender.

The watch app is a companion to the iPhone, not a standalone account. It talks to the paired phone over WCSession, never to a backend or a provider directly. Bundle id com.epistles.watchkitapp.

Yes, on Samsung Galaxy Watch, Google Pixel Watch, and any compatible Wear OS 3+ device. Feature set matches the Apple Watch app: full triage, voice or template reply, "Reply & Done", agenda + RSVP, plus a Wear OS inbox tile. It pairs to the Android phone over the Wearable Data Layer and does not speak to a backend or a provider directly. Bundle id com.epistles.wear.

Epistles is the only third-party email client shipping a feature-complete app on both Apple Watch and Wear OS with parity. Newton had Apple Watch but never Wear OS; Spark is Apple Watch only; Mimestream, Mailbird, Thunderbird, and Canary Mail have no watch app at all.

Yes. A single in-app wizard takes your Apple ID and an app-specific password and provisions two adapters from the same credential: IMAP for iCloud Mail and CalDAV / CardDAV for iCloud Calendar and Contacts.

There is no Sign in with Apple option, deliberately. Apple has no public OAuth program for iCloud Mail, Calendar, or Contacts data; Sign in with Apple is identity-only and cannot read mail or calendars. An app-specific password is the only path that actually works.

Yes, via CalDAV against iCloud. The same wizard that adds Apple Mail also adds the calendar: one Apple ID + app-specific password provisions an IMAP account (Mail) plus a CalDAV / CardDAV account (Calendar + Contacts). It's the same protocol Apple's own Calendar app speaks; Epistles talks to it directly instead of routing through macOS Calendar.app.