1. By an "Insider".
2. By a pretty standard "Phishing" ploy.
Add to this the Wikileaks/Assange assertion that it was "Not the Russians" and we have a pretty good case for our claim of "Fake News". To prove otherwise to me would take some solid proof of a a Russian-Wikileaks connection. I don't expect to find that. Ever.
But the Insider vs Phishing issue remains. I wonder if we will ever know for sure.
I think it’s pretty well-known that the Podesta leaks were phishing. We have the emails and links he clicked. The DNC emails are of unknown origin. They could have been an insider (as Assange has asserted) or a hacker. I believe Assange.