Hello everybody, i have two Exchenge Server in a frontend backend konfiguration. The frontend is in the DMZ and is published over the external Adapter on an ISA Server. The backend is in the corporate Net. The ISA Server has tree Adapters(Internet, DMZ, corporate Net) but now i want to use a second Server for a "back-to-back" DMZ. What do i have to do that the communication between the two Exchange Servers is still working??? Configuration?: ISA 1: Internet: 213.218.100.2 DMZ: 10.1.1.1 Frontend: DMZ: 10.1.1.3 ISA 2: DMZ: 10.1.1.2 corp. Net: 10.1.2.1 Backend: corp. Net: 10.1.2.35 When i have to publish the backend Server then i have to give him an IP-Adress from the DMZ but then my frontend doesn't find him anymore because on the frontend is a DNS Server running with the Zone of the internal Net. Is it posible to make a 2'nd host entry for the backend with the publishing Adress? Thanks for help, Guido Neubecker