After couple restarts Mail server with Exchange 2007 started having issues with OWA with NTLM authentication. Internally all users can connect to it within Outlook. Externally Outlook complains about certificate. First error I have seen was code 2. When I removed already installed certificate that was on computer I was using Outlook and re-add it then error code 8 appears saying the Certificate is invalid. There were no changes to any of the certificates and only one certificate is installed on the mail server.
I have involved Microsoft but so far no luck with them.
Server is Windows 2003 R2 and Exchange 2007 SP3 Rollup 12.