Thanks for the response.
That is a shame that it ISPConfig does not work with LDAP for virtual users.
I have to have an LDAP solution and I really liked the ISPConfig interface.
Thanks for the clarification on the firewall aspect.
I saw a HowTo for CentOS 5 with LDAP, Dovecot and Postfix. Is there a plan to update that for CentOS 6?