I'm not exactly a defender, I'm more a person who wants to look at the facts. I think there are two main reasons Clinton used a personal server. The major reason, in my opinion, is that, because she has had 30 years of nonstop hostile investigation of her every word, on tape or on paper, she wanted to keep tight control over her correspondence, knowing that it would be presented, out of context, before the public and numerous hostile Congressional committees, and possibly, to a special prosecutor. The second reason is that it followed SecState precedent set by Rice and Powell, the latter of whom actually wrote to HRC recommending she use a private server (though Powell later denied this, the email exists). Powell also refused to hand over emails to a committee, and destroyed emails (that probably were personal business). The Democratic Committee didn't make a big issue of it, if you are in tune to contrasts.

So, I'm not perplexed. HRC's suspicion, if it is paranoia, is justified.