autoexpunge creates special_use folder

[Tom Sommer]

namespace inbox {
   mailbox Spam {
     special_use = \Spam
     auto = create
     autoexpunge = 30d
   }
}

This creates the "Spam" folder in the filesystem on login/logout, even 
though it shouldn't.
If I remove autoexpunge, the folder is not created.

-- 
Tom Sommer