I find e-mail preferable to other methods of communication in ways other than convenience. One advantage is that information is laid out all at once. It is easy to return to an earlier part of a message or even refer to a previous e-mail. On occasion, when I need to refer to a conversation from months ago, it's easy. Furthermore, this record-keeping requires no extra effort on my part.
People say that e-mail is a bad means of communication because it is impersonal.
However, in many ways, I think e-mail is very personal. The flip side is, that in order to write e-mail, you have to know what you want to say and how you want to say it. If it is not carefully worded, it can easily be misunderstood. Without the author present to clarify wording, people can be angered and offended. Good e-mail, however, is crisp, clear, and to the point.