There can be huge differences between private email providers, and most of those differences are outside the control of government personnel. Clinton's setup was reviewed by State IT folks, and the third party contractor that maintained it did so according to government guidelines for security patches and data backups. She violated policy, but she did so openly and with the full knowledge of State IT and Security offices, as well as the full knowledge of every person who ever sent her an email to the clintonemail domain.

For the purposes of records retention, a private email server is provably BETTER than a private email provider, because it can be set up to conform to archival guidelines as opposed to being set up for arbitrary business purposes. This is true in both theory and fact (guess how many of Powell's work emails were archived and are now available for government historians? the answer is ZERO). NEITHER meet current government policy, though, but if you intend to delete emails, trust me the delete key works just fine for all practical purposes on private email providers, and is often set to automatically delete things older than 6 months. Yes you *might* be able to subpoena that provider for backups, but the power of subpoena also worked just fine on Clinton's server backup tapes, and even many of the emails that were deleted (properly) were able to be recovered.

With regards to security, well the State Department unclassified email server ACTUALLY WAS HACKED by the Russians, while Clinton's was not. In another incident, the Office of Personnel Management lost tens of millions of records regarding security clearances to a Chinese hack. Cybercrime affects private and government email servers with little regard for who is paying the bills. In some ways her server may have been more prone to attack than a typical government server (since she was a high profile public figure), but in other ways it was also less prone (there were so few accounts and the ratio of administrators to accounts/volume was very high). A private email server also has potentially dozens or hundreds of insiders (many who may be foreign nationals), while Clinton's email server only had a few sysadmins who were all individually vetted.

I find none of these various differences and details to be that compelling, though. The bottom line is she violated government policy on how to handle her email, and it was wrong for just that reason (not because of any bad thing that happened as a result of the decision, which is basically almost nothing compared to what happened to the State Department system itself). It was something that was done wrongly, but ended up causing no real harm, a conclusion the FBI agreed with. And unlike Mr. Trump who still insists Obama was born in Kenya, she has admitted her error and does not stand by it.

She did so openly and with the knowledge of everyone at the time, so if it was a monstrous scandalous terrible thing that was going to end the world and result in massive security catastrophes then perhaps all those IT and security experts who helped set it up and watched it in operation for her entire tenure were really negligent, as was Congress who was fully aware she had a private email address the entire time (it is not like she was concealing her email domain). All in all it is a bunch of sound and fury signifying nothing.