Hillary was more than welcome to have a private email account to communicate non-government business with friends, family, outside business, etc.
Any .gov related emails should have been run through .gov email, and for the odd time that .gov business was sent on her private email account inadvertently or out of necessity (shouldn't be classified in any respect obviously), she should have copied her .gov email address for public record.
This is supposed to be SOP for all .gov employees. I worked for the state for awhile after the bubble burst. If I needed to email somebody I copied my work email (but I obviously didn't want to email from my personal account because I knew it would be public record). If I didn't want it in writing, I didn't put it in writing.
Same goes for Ivanka, or Donald, or Spartacus.