The first point is that forensic computer examination is expensive. It has reached the point where no two computers are identical. Some have one update, some another, some are running older or newer versions. Sometimes we can select a specific commercial program to permits us to access the information. To examine information stored on a computer it is irrelevant if someone has 'deleted' it, as a simple deletion, by itself, just removes the link to the information, not the information itself. You need a report that would hold up in court, you need experienced professionals whose affidavits will hold up in court. You need the latest tools to search your programs. Many types of computers can be examined these include your Macs, Apples, towers and laptops, tablets and iphones. Some more successfully than others. The retrieval of deleted information is restricted by many things including how long since the information was deleted and what has been done to the computer since that time, as well as what operating systems you are running. There are methods available for possibly backtracking harassing emails, however, without guarantee. We cannot access a remote computer without access being granted. Do not let that 'helpful' friend, who knows a 'few tricks' work on your computer, or any digital storage device. The less activity, the less use, the less interference, the higher the probability of success. We have the specialists available, Computer Forensic Analysis.
PLEASE NOTE: WE DO NOT HACK PEOPLES FACEBOOK ACCOUNTS, NOR OTHER PEOPLES TELEPHONE RECORDS. We cannot guarantee any search until after it is done.