Gahh! I'm planning a move from macOS to some Linux-based OS once this laptop dies. I've had 20+ years of using Mail.app and thought that Thunderbird would be the appropriate replacement.

But that link, and the comments at https://connect.mozilla.org/t5/ideas/thunderbird-should-by-d... ('Given that significant parts of Thunderbirds user interface (addons manager details, welcome page, whats new on updates etc) are essentially served as web pages into Thunderbird, perhaps your expectations are becoming unreasonable.') tell me that Thunderbird does not respect my desire to minimize my info leakage to the outside world.