When the second part comes out, I hope that you will address using OWA forms-based authentication (FBA) on the Exchange Server side. We currently have two NLB Exchange front-end servers on the inside serving OWA 2003 with FBA. We would not want to build a third Exchange server or a second pool of servers just to have a place for ISA to communicate, as would be implied by most of what I have seen in regards to configuring for ISA. Http://www.microsoft.com/technet/prodtechnol/isa/2004/plan/owa_radius.mspx says, "When configuring ISA Server 2004 with Exchange Server 2003, you can enable forms-based authentication on ISA Server or on the Exchange server, but not on both." But, I haven't seen how to configure ISA to use FBA on the Exchange server. In short, how do you set it up so that both internal and external users can use forms-based authentication?