People are all over discounting email as a useful communication medium. The only difference between email and paper memos is the ability to send them so quickly. In another job, I usually sent important emails to my boss who then rewrote them to make them more palatable for the wide public. In the end, knowing the audience and not trying to assume and contacting the author when clarification is needed (not by email).
Though e-mail is a powerful and convenient medium, researchers have identified three major problems. First and foremost, e-mail lacks cues like facial expression and tone of voice. That makes it difficult for recipients to decode meaning well. Second, the prospect of instantaneous communication creates an urgency that pressures e-mailers to think and write quickly, which can lead to carelessness. Finally, the inability to develop personal rapport over e-mail makes relationships fragile in the face of conflict.