Topic: CAS authentication

==== Required information ====
- iRedMail version: 0.7 and 0.8.2
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Linux/BSD distribution name and version: ubuntu 12.04 64bit
- Related log if you're reporting an issue:

Is it possible to use CAS server to authenticate and if yes where can I start from?