[imp] flag & folders trouble

[webmaster at lucas.at]

Hello,

I am unsing a Qmail & qmail-pop3d installation using maildir, and just
installed HORDE & IMP.

everything works fine but just on problem appears.

The only Folder i can see is the INBOX-folder.
But i want to use sent items too.

How can i get this done?
i have:
$conf['user']['allow_folders'] = true;
$conf['user']['select_sentmail_folder'] = true;

The other one is that the "flags" don't work.
What i mean is:
Mark Mail as read, unread and so on.

I am really very new to that whole mail thing, but i guess this error
shouldn't be hard to fix for experts like you.

Thank you very much,
lucas