Hi,
we use ucs also as global adressbook. works quiet perfect. in Thunderbird we can set ldap filter like this:
but stupid outlook cant… so in outlook it shows all objects 
is there any chance to filter ldap output on server side?
Hey richie,
the servers response to LDAP requests can be restricted via LDAP ACLs.
There usage is described in our manual: 3.3. LDAP directory — Univention Corporate Server - Manual for users and administrators
Another point to get some clues might be guides in this forum like How-To: Use LDAP ACLs for Selective Replication or Restrict read access for students.
Best regards
Jan-Luca