They did not wipe all the emails. Her team sorted through to send only the ones which were subpeonaed, which is what you are supposed to do.
And the DNC hack is what the original post probably meant, but people mix all this stuff up. Those were published on Wikileaks and generated super productive controversies, such as pizzagate.
And it isn't illegal per se to use private email. It's extremely common, but should be cracked down on. A big problem with it is age. Try telling your grandma she has to use a different email when she contacts you about certain topics.
Criminal intent is required for all crimes except those which are strict liability.
And you really ate the propaganda on the rest, not sure what else to say.