Essentially email is no different than paper or verbal communications with the same weaknesses if things are unfocused, unclear, and/or unnecessary. Because of its accessibility, email has just magnified those problems when those standards in communication are allowed. The key is having a culture and relationships that have established (really) the best-practice standards, such as communicating on purpose, while respectful of others’ time and attention. Then, it’s a lot easier to ensure that happens within all the media, including email. If you don’t have those standards, I’ll bet it’s not just email that has those problems.