Is there a way to prevent internal candidates from applying to the external site?

Summary:

Is there a way to prevent internal candidates from applying to the external site?

Our HR team stated the following: We noticed today that even if we do not post to our internal website candidates applied internally. They are going to our website and applying that way and coming through as internals. Does ORC have the ability to block @ah4r.com and @amh.com from applying and only allowing to apply if/when through our internal current jobs/internal market place?

Please note they are just speaking about applying via our career site. They are not asking to globally block @ah4r.com and @amh.com as those are our company domains. They just want the ability to prevent internal Canidates from applying to a position that is meant only for external