Re: Spot the oxymoron
The emails are reported to contain classified material. That is consistent with the Clinton campaign claim that the messages were not classified, but almost certainly indicates either carelessness or malfeasance within the State Department that reaches the Secretary's office if not the Secretary herself.
Of course none of it would have been much of an issue if she had not, violating both law and regulation, deployed a private (not to say quite insecurely configured) server to conduct government business. Instead, she would have done email on State Department systems either in the office or remotely using a government provided VPN and examined classified information either in hard copy or using systems attached only to a secure network that did not interface with the public internet (and secret and above possibly in a physically secured and electromagnetically isolated interior room).
Every article I have seen, including this one, treats this much more lightly than it warrants, as do a large fraction of comments, both here and elsewhere.