Configuration is: Client Machine: Client > ISA > CheckPoint Firewall > Internet Server: Ex2K > ISA (Separate machines - Ex2k being server published) > Internet This is the problem: From the client PC *going through ISA*, if I try and open an Ex2K OWA session, it fails - Browser error is 'Access is Denied' If I configure my browser *not to go through ISA* (i.e. straight to the Checkpoint) it works just fine. My gut feeling this is something to do with 'Digest Authentication' what do you think ?