I think ti would be great if you were able to make the dividing bar which sits between the folder view and the message list dragable to resize the split between the areas. I have some nested folders and in this case the interface becomes unusable. Of course you'd also need to store the position of the bar in a cookie for next time a user logs in. :)
I agree.
Did you create those folders in roundcube, and if so how, or were they pre-existing?
Thanks!