[Dovecot] Creating an IMAP repo for ~100 users need some advice

Hi,

I am currently in the process of setting up an IMAP repository for round 100 users....

Currently the user authentication method is being handled via a Windows Domain Controller.

The host OS for Dovecot will either be FreeBSD or CentOS.

Would Dovecot be able to authenticate to either the DC directly or would we need to go through LDAP??

Additionally what would be the best method to store the **mail** information? - as in MySQL database or Maildir format; coinciding with this what is the best backup method in order to be able to do 'dump' backups or restore single emails??

Can anyone give me a hand with this?

Regards,

Kaya