FOLD Documentation
Early access
Updates and releases

Updates on the Mac

The direct download keeps itself current through a signed update feed on foldmail.app, while the TestFlight build is updated by Apple.

Note This page describes the direct download from foldmail.app. If the download page shows No public build yet, or foldmail.app offers early access instead, that build has not been published.

Automatic checks

The direct download contains an updater based on Sparkle 2. With Check for updates automatically turned on, FOLD looks for a new version shortly after launch and then once a day. It fetches a single update feed from foldmail.app. If foldmail.app cannot be reached, nothing visible happens and FOLD tries again at the next check.

When a new version is available, FOLD tells you and installs it once you agree. Updates may be delivered as small delta packages instead of the full app.

Checking by hand

  • Menu: Fold > Check for Updates… starts a check and always shows the result, including when you are already up to date.
  • Settings: Settings > General has an Updates card with Installed version, Last checked, the switch Check for updates automatically and a Check now button.

How an update is verified

The card sums it up: “Updates come from foldmail.app. Every package is verified against the signing key built into FOLD before it is installed.” FOLD accepts only packages signed with the matching private EdDSA key and rejects anything else, even if it comes from foldmail.app. In addition, every disk image is signed with the Developer ID of Datargo GmbH and notarized by Apple, so Gatekeeper checks it as well.

A published version is never replaced, only superseded by a newer one. A version number therefore always refers to the same file and the same checksum; see Verify a download.

What the check sends

The check downloads one static file from foldmail.app. It carries no account, no identifier and no system profile; the server sees an ordinary HTTP request. If you turn off Check for updates automatically, FOLD only checks when you ask it to.

TestFlight and App Store builds

The Mac build that Apple distributes through TestFlight has no built-in updater. It shows neither the Updates card nor the menu item, because Apple does not allow store apps to replace themselves. This build is updated through TestFlight. A version from the Mac App Store would likewise be updated only through Apple.