Typically, companies have a policy that says when you are accessing company information and using company systems, then you forgo any right to privacy. Where the company does not have rights is to personal email accounts or personal storage devices. If they think there are data in these areas, they may not have an immediate right to look and need to get the court involved.
When asked about employees checking their personal email at work, Droke replied:
It’s a gray area. There are times when that account and the email that is on it will create a shadow image onto the hard drive, and the law still says that if the employee is working on the company’s computer, then the company may still have the right to that information.