Two LDAP entries with the same attributes, but not the same attribute values, are recognized as the same user type.
The case in point is a regular user (with, for example, `nsroledn: cn=imap-user,%(base_dn)s`) an 'admin-user' (with, for example, `nsroledn: [ cn=admin-user,%(base_dn)s, cn=kolab-user,%(base_dn)s ]`) which are both typed as the regular user.
Adding a field attribute definition for the `nsroledn` to be of a format `cn=admin-user,%(base_dn)s` should allow the admin user to be recognized as such.