FOLD Documentation
Early access
Security and privacy

Data on your device

What FOLD stores, where it stores it, and what it never collects.

FOLD is a local mail client. Everything it keeps lives on your device, in FOLD’s own app container; there is no FOLD server holding your mail or your settings.

The mail store

FOLD keeps these parts in its app container:

  • Account database: accounts, identities, folders.
  • Header database: sender, recipients, subject, date, flags and a short preview per message.
  • Message cache: the full messages including attachments, as downloaded from your server. Each file is stored under its SHA-256 hash, and FOLD checks the hash every time it loads the file, so a changed file is detected.
  • Search index: the full-text index used by search.
  • Outbox: messages waiting to be sent.
  • Public keys: your correspondents’ OpenPGP keys.

On the Mac, the container sits inside your user library and is protected by FileVault if you use it. On iPhone and iPad, the store is excluded from device backups and protected by the system so that it cannot be read before you unlock the device for the first time after a restart. Fortress Mode adds a second layer with your own passphrase.

The keychain

Secrets never go into these files. FOLD keeps them in the system keychain, readable only while the device is unlocked and bound to this device:

  • account passwords and OAuth tokens,
  • OpenPGP private keys and, if you choose, their passphrases,
  • S/MIME identities (.p12) and their passwords,
  • the Fortress master key, if you unlock Fortress with Touch ID or Face ID.

None of these items is synced to iCloud. The only exception is the optional password sync, which copies account passwords, and nothing else, into your iCloud Keychain after you agree to it.

Spotlight

FOLD adds your messages to the system search index on this device, so Spotlight can find them by subject, sender, recipients and preview. The index is protected by the system and stays on the device. Fortress accounts, drafts, spam and trash are left out. FOLD has no setting to switch this off yet.

What FOLD does not collect

FOLD contains no analytics, no telemetry and no crash-reporting service. Its privacy manifest declares no tracking and no collected data. The activity log on the Mac is kept in memory only; FOLD does not write it to a file.

Which servers FOLD contacts, and when, is listed under Network connections.