If you are using your company's email, computer, network, etc., you should have no expectation that anything is private...it all belongs to the company (in most cases).
I don't have expectations that anything computer related that I do at work is completely private but I don't expect my co workers to be able to access my accounts or those of the higher ups. She not only hacked into students and professors accounts but also that of school administrators. Who knows if there was sensitive information in the emails of the administrators such a performance reviews of professors, information about salaries, lawsuits, etc. She accessed and kept notes on information she didn't need for her job and had no right to.
My work email address was once inadvertently added to a list of emails belonging to the trustees (including the president of my company) of the place I work. The email contained a summary of a previous trustee meeting. I quickly emailed the sender and pointed out the mistake. Sure, it might have been interesting to hear 'inside information' but I didn't want to be accused of anything.
I know for a fact the our IT dept monitors the accounts- someone was fired for accessing porn sites; another was reprimanded for allowing his account to be used by someone else to make offensive statements. I'm afraid that all they get from my account are recipes and hair tips (sorry that I'm not more interesting, IT guys!).
