Have you done Natural Language Understanding?

[Cirrus]

Maybe you need something like Watson: https://personality-insights-livedemo.mybluemix.net/

I had a look at MS LUIS as suggested above but it looks more like pulling out themes from lots of documents rather than 'recognising' the type of individual document. So it would be good at finding out what themes are connected with Adele's left foot on social media or saying "If you're interested in Adele then everybody is talking about her left foot."

Watson seems a bit similar. If you asked it "how many feet does Adele have when she's holding a baby?" it might get the right answer. However the challenge I have is : here are 10000 emails and the category they have been assigned to - can you spot the pattern?" I've only seen that with Neural Networks eg card fraud detection.

[DimPrawn]

This is the most applicable API I have found so far for text analysis

MonkeyLearn - Machine Learning for Text Analysis