SSSD Active Directory

Has anyone tried to implement Active Directory support? I have a window active directory server running and
several linux ubuntu clients that can authenticate against it using SSSD (

How is the current user/pass system working, it seems to be some kinda custom sqlite ? i guess it would be possible
somehow to get dovecot to auth against sssd but actually having mailboxs setup for certain users automatically is
probably tricky,

any thoughts welcome,