01 · One inbox
One inbox.
Every account you own, every address you answer to, in a single client.
Six inboxes. One quiet desk.
est. 2026
Every inbox one place.
A mail client that speaks Fastmail, Gmail, Microsoft 365, iCloud and Proton in their own native protocols. Every account, every device, including the one on your wrist. Stored on your machine, encrypted at rest, searchable offline.
Mac · Linux · Windows · iOS · Android · Web Apple Watch · Wear OS
At a glance
Three things, said plainly.
What Epistles is, in one breath.
02 · Native protocols
Native protocols.
Gmail API, OWA, JMAP, iCloud, Proton, IMAP. Each provider spoken in its own dialect, nothing flattened.
03 · On your device
On your device.
Mail lives in local SQLite, encrypted by your OS, searchable in milliseconds. The relay never reads a word.
Many lives, many addresses
You don't live one life.
So why run one app per address?
A day job. A side project. An alma mater that still writes. A nonprofit board, a personal address, a newsletter you half-meant to start. Each address arrived with its own app, its own password, its own dock icon. Epistles gathers Gmail, Microsoft 365, Fastmail, iCloud, ProtonMail, and any IMAP account into a single client.
On your wrist
watchOS
Wear OS 3+
Both wrists. Same inbox.
Spark and Outlook ship Apple Watch only. Mimestream, Mailbird, and Thunderbird ship no watch app at all. Epistles is the only third-party mail client with native companions on Apple Watch, Galaxy Watch, and Pixel Watch — same triage on every one.
- Triage on the wrist. Archive, snooze, pin, forward to a contact, "Reply & Done" in one tap. Dictation or saved templates for anything longer.
- Today's calendar, one tap to RSVP. Beside the inbox where the invite arrived.
- Complications and tiles. Unread count and first sender, on the face or in the carousel. No app launch.
- Same six providers as the desktop. Gmail, Microsoft 365, Fastmail, iCloud, Proton, IMAP — all readable from your wrist.
Why Epistles
Many accounts. Many platforms. One client.
01 · Every account, one client
Many inboxes. One keyboard.
Every account lives in the same client, behind the same shortcuts, composer, and command palette. Each message wears a quiet chip naming the address it arrived at. The single combined list lands later this year; the keyboard is one already.
Personal · 24
Work · 8
University · 3
Side project · 12
02 · Mail, calendar, contacts
A letter rarely travels alone.
Epistles reads each provider's calendars and address books beside the mail. The meeting attached to a thread, the face attached to a name, and the message itself sit one keystroke apart.
MailMany providers, one client
CalendarGoogle · Microsoft · Apple iCloud · Fastmail · CalDAV
ContactsGoogle · Microsoft · Apple iCloud · Fastmail · CardDAV
03 · Local-first
Your mail. Your device.
Every message lives in a local SQLite store, protected at rest by FileVault, BitLocker, Data Protection, FBE. Search runs against the cache: milliseconds, no round trip, no signal required. The relay only touches what needs a wire, and never a word of the letters themselves.
OS disk encryption · AES-256-GCM Cloud Vault · zero-knowledge
04 · Six platforms today
Six platforms. One codebase.
macOS, Linux, Windows, iOS, Android, and the web — shipping today. Sign in on a new device and your accounts are already waiting, carried across by the zero-knowledge Cloud Vault. Credentials travel as ciphertext; only your password unwraps them.
macOSLinuxWindowsiOSAndroidWeb
Polyglot by design
A native tongue for every provider.
Other clients flatten everything to IMAP and lose half the features in the trade. Epistles speaks each provider's own dialect — threads, labels, flags, push, calendars, contacts — nothing flattened on the way in. See how Epistles compares.
Gmail
Gmail API
Microsoft 365
OWA
Apple Mail · iCloud
IMAP + CalDAV + CardDAV
Fastmail
JMAP
ProtonMail
Proton + PGP
Anything JMAP
JMAP
Anything IMAP
IMAP / SMTP
Our promise
Your email belongs to you.
Local-first, by design. Encrypted at rest, by your OS. Synced across devices as ciphertext only your password can unwrap.
Mail lives on your device. Search runs on your device. The relay does two things: a zero-knowledge Cloud Vault for credentials and settings (we store opaque ciphertext we cannot read), and the push and read-receipt metadata you opt into. OAuth refresh tokens are the lone carve-out, held server-side so one device's refresh can't brick another's.
- Zero email content on our servers. Bodies, attachments, drafts: yours alone.
- Credentials wrapped in a zero-knowledge vault. Only your password unwraps them.
- Proton's PGP model, intact. Private keys never leave the device.
- No telemetry, no tracking, no ad model. No third-party SDKs in the build.
The carve-out: Gmail and Fastmail OAuth refresh tokens live encrypted on our backend so we can rotate them centrally and keep multi-device races from killing your sign-in. Deliberate trade. Everything else stays zero-knowledge.