Maybe the answer is that she wanted China and Russia to read her mail. It's just an expansive head-fake to help them feel comfortable with American diplomacy, because they think they know what you think, but you really know that you said what you wanted them to think you thought on a server they could easily hack into and read.
I mean, that's what I'd have been doing if I'd done this. It's key, though, that they don't think she's smart enough to out-think them. And I think she's got that part of the play down.