*** bug 201157 has been marked as a duplicate of this bug. ***

Do you have any proposals for the IDL?

yes, i'm working on this now.

in EvolutionStorageListener:
  void notifyHasSubfolders (in string path,
                            in string message)

in EvolutionStorage:
  void asyncOpenFolder (in string path,
                        in Bonobo::Listener listener)

The mailer would create the storage and then do
evolution_storage_has_subfolders (storage, "/", _("Connecting..."))

The shell would create the storage, closed, with a child whose
label was "Connecting...". When the user opens the storage, the
shell does an asyncOpenFolder, at which point the mailer tries to
connect and fill in the folder tree. (As soon as it adds a real
folder, the shell will remove the fake "Connecting..." node).
When the mailer is done, it sends back success/failure via the
listener. If it fails, the shell re-closes the storage.

The "has subfolders" call can also be made on a folder inside the
storage, so that evolution-exchange-storage can fill in each level
of the public folder hierarchy as the user opens it, just like
Outlook does.

Fixed in CVS.