Auto Discovery Fails for All Users with the Error Code 0x80072F0C

Clients usually experience this problem due to the deference of how Client Certificates and SSL Server Certificates work.

• SSL Certificates provide the functionality of Encryption and Security
• Client Certificates provide the functionality of Authentication

Though the two technologies both use certificates, they are not related directly. WINHTTP is the mechanism that's used to connect to the web through SSL. When running in NATIVE MODE, the client attempts to ignore the SSL Certificate and use the Client Certificate, which results in a failing connection to webpage that requires SSL.

This problem could be resolved through the following

1. Expand the "autodiscovery" hive on the IIS Management Console
2. In the middle pane select "SSL Settings" for the autodiscovery virtual directory.
3. Under "Client Certificates" make sure the option "Ignore" is selected instead of "Accept" or "Require"

This should resolve any Auto Discovery related problems with clients if you have configured the Autodiscovery on the Exchange Server Error free..