[Dovecot] Maildir

I have been trying to set up dovecot with postfix to use at work. I'm trying to configure dovecot to authenticate against active directory and postfix the same. I installed dovecot 1.0.10 on FreeBSD 7.0 beta 2

When I telnet in the get authentication ok but an error suggesting that there is no Mailbox belonging to that user. I am using Maildirs. How can I now create a Maildir with the proper permissions for that virtual user?

Thanks for any assistance.