We are running exchange 2010 and one of our end-users just recently purchased a windows 8.1 laptop. When he tries to connect to exchange using the built-in mail app, he gets the error, "To connect to this account, you need a valid certificate on this PC. Contact your system administrator for more info"
I searched a lot online and found a suggestion of signing into OWA and exporting the root level certificate, then installling it. I did that, but still receive the error on his machine.
Any suggestions?