It's A Known Fact That Network Admins Can See, Read, Delete, and Block Emails

The super admin can view all and see all. The super admin is the god of his computer network. You can find out what mail he deleted by longing into his account and recovering his deleted items. Only company policies and actions can prevent this in the future. There should be more than one administrator watching over the network and then each of them should be running on a policy to blow the whistle and watch out for those troublesome Admins. Privacy is important nowadays and so even System Administrator Gods should be warned.