This is an issue I hadn't seen before.
When I try and preview an email or file internally I only see the name of the document or email and not the content. If I preview the document or email externally I see the content. This includes not seeing anything in the preview tab, raw data, properties etc.
Interestingly when I run a keyword search it does find data, so that would indicate the indexing has been successful.
Any help gratefully accepted. This is an urgent case by the way (Aren't they all)