Of course, Thunderbird on Android and Thunderbird on Desktop are both intended to serve very different form factors, so there will be UX differences between the two.
Of course.
Drecking.
It should be illegal to print a QR code leading to a different URL than the one printed next to it.
Always include what you forget.
It's far from obvious what's obvious.
Serious.
test/unit/response-buffer.cpp includes the complete lyrics of Rick Astley's "Never Gonna Give You Up".
To the best of my knowledge, this song hasn't been released under a free license, so... You know the rules (and so do I). A full lyrics removal is what I'm thinking of.