> Betterbird: Yes!
> Thunderbird: No, requested since 2003
Wonderful! Back in the mid-2000s, this annoyed me enough to switch from Thunderbird to Outlook for work mail. Great to hear they had to fork the project to match the delicious UI of Lotus Notes.
Honestly since then I haven't thought much about local PC mail clients to even consider any alternatives. Apple Mail and web mail work fine.