Very interesting read and, in my case, it has proven to be as close to truth as it can be. Go read the whole thing, it is worth it.
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.