How do I disable telemetry in Thunderbird?

I'm running Thunderbird 91. I noticed in the JS console that the app is collecting some kind of telemetry about me and sending it somewhere! Noooo... !

How do I disable it?

Solution 1:

This is what I did, based partly on this thread:

1. Go to Edit | Preferences (or Tools | Options, or Tools | Preferences) on the main menu, or Preferences on the Hamburger menu.
2. Locate the Config Editor button and press it.
3. Set the following preferences to false:

   dom.security.unexpected_system_load_telemetry_enabled
   network.trr.confirmation_telemetry_enabled
   privacy.trackingprotection.origin_telemetry.enabled
   telemetry.origin_telemetry_test_mode.enabled
   toolkit.telemetry.archive.enabled
   toolkit.telemetry.bhrPing.enabled
   toolkit.telemetry.ecosystemtelemetry.enabled
   toolkit.telemetry.firstShutdownPing.enabled
   toolkit.telemetry.newProfilePing.enabled
   toolkit.telemetry.shutdownPingSender.enabled
   toolkit.telemetry.shutdownPingSender.enabledFirstSession
   toolkit.telemetry.updatePing.enabled
   toolkit.telemetry.unified
   

4. You can try, but probably fail, to set the following preference to false:

   toolkit.telemetry.enabled
   

5. Set:

   toolkit.telemetry.rejected = true
   toolkit.telemetry.prompted = 2
   

6. To be on the safe side, set

   toolkit.telemetry.server = http://no-such-frigging-server.kthxbye/
   

I don't know if that covers everything; hopefully it does.

Solution 2:

Much simpler is go to preferences and type "data" into the search field. Your settings are shown thusly