[horde] Configuration or version question?

[jic at netgate.com.uy]

Hi.
 I using horde-2.2.3-1 and imp-3.2.1-1. In the demo site i saw a tree 
displaing the folders and other stuff on a left frame. My question is this 
"Can I enable this option in my version or this options is supported only in 
a new version?"

Tnks.
Jose I. Callero