PLEASE can anyone help me. Had to replace the network card for internet connx yesterday and this blew up ISA, so have reinstalled ISA + SP1 and everything is fine again except OWA. Exchange is working fine mail is coming in and out no prob. When trying to access OWA I get the error 500 Internal Server Error - The target principal name is incorrect. (-2146893022) Internet Security and Acceleration Server I have never seent his before. Accessing OWA internally using https://[servername]/exchange is fine, only when using https://owa.[domainname].com/exchange do i get this. I think it is something to do with the certificates? It is using one published from a local certificate server, and the "certificate is ok" on both E2K and ISA boxes. SSL bridging is working properly I think? So OWA is there and running, just can't access from externally? If you try to access http (no SSL) you get the page from E2K IIS saying you need SSL so it seems it is getting through okay? Please help. If you need more info email me direct and I can send you the link so you can see for yourself.