As if there weren't enough reasons to use the old tried-and-tested Firefox/Thunderbird combo over the competition... I've just installed a new SSD in my main PC and changed the OS from Windows 10 to Ubuntu. I copied the Firefox and Thunderbird profile directories over without modification and both pieces of software just work as if nothing had changed. All done locally and without having to sync with an external cloud service. I'd like to see Chrome/Edge/Outlook/GMail do that.