Yes, but as has been pointed out several times today, those .gov accounts aren't secure. They have other ways of dealing with classified stuff. Comey explained that.
I suspect that if somebody really wanted to waste a lot more taxpayer money, any investigation he launched would ferret out all kinds of government people--elected and unelected--who've not handled their email altogether properly.
So after today's news, all we really knew was that she did something stupid. But we've known that from the beginning.