Hello NG, I want to use the OWA Password Change with Exchange 2007 over ISA Server 2006. I have got an AD integrated Server 2008 R2 PKI. The password change between ISA and the DC of my domain works over Secure LDAP. I need a certificate for the LDAP Server (Microsoft 2008R2 DC). What kind of certificate do I need? Is it a Domaincontroller certificate? I dont want to enroll certificates for all my DCs by GPO with automatic distribution of the certificates and I dont have the certsrv Website installed on my Microsoft PKI. What kind of certificate do I need? What is to do to get a certificate on the DC? Best Regards Tobias