I agree threads are trees, but what I mean is the last 10 roots of
trees.
They can change of course, as some people will reply to messages or
create new ones; but at one point in time, I want to see the last 10
topics, the last 10 trees' roots, the last 10 threads, ...
Is there a way to query IMAP for this? Or do I have to ask for ALL
threads and filter on client side?

Maybe it's not possible to do?

Thanks,
Greg