Not if it was sent to and email on her home-brew server which the recipient had access to. It could have been read, then deleted off her server. Or cleverer yet, she saved it as a draft on her server and someone read and deleted it without it ever being sent.
Not her server their server. People who sent or received e-mails and texts to or from Hillary have hard drives and ISPs.
There would be a record on the sender/receivers email server though, unless they were pulling the same stunt as Hillary!.