When running Spotlight in SSL environments
If you are running in an SSL environment, you must add the SSL certificate from the root CA to the SharePoint certificate store, or else the Spotlight Processing Job fails with an error like the following:
Error generating user profile cache for spotlight. System.Net.WebException: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel. ---> System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.
You can do this from Central Administration -> Security -> Manage Trusts -> New.