Thunderbird doesn’t passphrase-protect your PGP key. Though you can set a general password… For something less important, its OpenPGP may be convenient, given that if you send/receive email normally, there is metadata problem anyway. But if you need to play it safe, you may want to use gpg offline and paste ascii.

Increasingly more and more “phoning home” is not exactly comfortable, either: thunderbird-settings.thunderbird(.)net location.services.mozilla(.)com addons.thunderbird(.)net versioncheck.addons.thunderbird(.)net services.addons.thunderbird(.)net, etc. Perhaps people today, both users and developers, feel something like this is normal, because things were already more or less like this when they were born.

Re: Micro$oft - It might be that after raped by Google, the society has been desensitized and stopped feeling anything about “minor details.” Why worrying now? You use a Windows 10 passport account (what is it called?) just to log on to “your own” computer and also a Gmail account anyway, right? So bad news is, your privacy is almost zero already.