I find the ability to sub group folders in mail really useful however when the folders are shared the sub levels are not maintained, anyone receiving the shared folders has them displayed as a flat list of all the folders.
for example I have:
Bookings/Booking 1
Bookings/Booking 2
etc. with Bookings being a folder with each booking underneath as a subfolder...
But when I share the folders the recipients see:
Bookings
Booking 1
Booking 2
I suggest developing the sharing ability so that folder hierarchies are maintained for everyone who sees the shared folders.
Thanks