The emails were not on a Government server.
The emails were on a private/personal-use server.
Clinton said the emails were deleted.
Trump mentions the Russians.
Democrats accuse Trump of encouraging espionage.
You can't hack deleted emails.
If the emails were personal, it's not espionage.
Actually, the DNC first mentioned the Russians being the hackers. Trump simply mocked them (quite masterfully) and sent them careening off into conspiracy theory territory.