How can I create more ous or change existing ous with zimbra (preferably the web administration frontend). Is there a zimlet available? Or is is maybe best practise to use additional Classes of Service to group users into different groups?
It is always better to use additional COS to group users if your requirement is to group users to allow them different zimbra features and stuff. It is not best practice to play around with zimbra's LDAP manually (which can be done using LAM) as zimbra services are based on it.