All true, in my not-a-lawyer opinion. The important addition is that "fair use" is a defense that allows the use of copyrighted material in certain circumstances. Like a book review that includes an excerpt from a novel, the underlying material is still protected by copyright. It doesn't mean the material is "not copyrighted"---the whole reason fair use applies is because it is protected by copyright. Practically all emails and photos that contain any element of originality are protected by copyright.