OWA / Exchange 2016 / Passthrough

Hi all,

We have managed to get OWA and ActiveSync email working through UTM 9.509-3, which connects to Exchange Server 2016. We have set the authentication mode to 'form' and the real webserver mode to 'basic' but it doesn't pass the logon details, we then get the Exchange OWA logon screen and have to re-enter our logon credentials. On the Exchange Server we have enabled basic authentication. Has anyone managed to get it pass the logon details? It's not the end of the world but annoying for people to have to double logon.