[Exim] [Newbye] But can it do subfolders?

Hello everyone,

I've been using IMAP on the client end for a while, and appreciate
the possibility to create subfolders and set up filters to get
messages nicely sorted into clean drawers.

Now my provider on a fresh domain name has EXIM installed as mail
server, and I'm able to access it under Outlook as IMAP. But try as
I may, I'm unable to create a single subfolder in the inbox. I'm
able to create folders on the same level as inbox, but no subfolders.

I tried cleaning up the mailboxes and refreshing the mailbox
database, but to no avail.

Despite extensive Google search over the last three days, I was
unable to locate a satisfactory answer as to what user setup/exim
configuration/scripting trick was needed to achieve this.

Any pointers/help/links appreciated.
Eric Vautier