Prepare to transition away from Google Sync Google Sync doesn’t support OAuth authentication, 2-factor authentication, or security keys, which leaves your organization’s data less secure.

Migration from pre-exisiting non-flatpak installations In order to migrate from pre-exisiting non-flatpak installation and preserve all settings please copy or move entire ~/.thunderbird folder into ~/.var/app/org.mozilla.Thunderbird/.thunderbird In case Thunderbird opens a new profile instead of the existing one, run: flatpak run org.mozilla.Thunderbird -P then select the right profile and tick "Use the selected profile without asking on startup" box.

There are three migration paths:

The call signature for setting up enums in migrations has changed.

a cheat sheet is available showing how to convert example commands from the manual of filter-branch into filter-repo commands.