Think about the process of writing an email for a moment. How do you go about this task? Do you compose the email in one session without filtering what you want to say or the information you want to convey, only then to go back and reread and edit the email at some later date? Or (and perhaps mostly likely, at least for many people), do you compose the email and edit as you go, deleting phrases, substituting words, or changing ideas and adapting the information in the moment as necessary for the best possible communication?
Odds are the most common method of emailing is the latter where edits and alterations are made in real-time as thoughts, ideas, and information hits you during the composing process. Where the first example may be a relic of the past when typewriters or handwritten correspondence was the norm, digital communication and the capacity to edit, rewrite, and revise in the moment means greater maneuverability in creating moments for effective, streamlined, and more productive communication. Where writing and editing/revising were at one time two distinct processes, today these functions are more or less integrated into one function with a greater level of process efficacy.