I read a story yesterday from a British website I've never heard of citing an unnamed lawyer that Cambridge Analytica had the leaked Hilary emails a month before they were leaked and by extension so did the Trump campaign. That's too many caveats to post the article but I'm inclined to think it's plausible. I'll post it as a comment https://www.spectator.co.uk/2018/06/what-does-the-british-government-know-about-trump-and-russia/
The Spectator is a relatively respectable and established conservative news magazine in the UK. Good to see that they will publish something like this that is somewhat critical of the present (horribly incompetent) Conservative government. But yes, the story about CA having the emails a month before Wikleaks needs more detail and independent corroboration before we can treat it as fact.