Most executives are struggling to cope with an information overload. The number of emails one gets per day in a reasonably sized organization is not funny. Many executives claim that a fair amount of their time goes in writing and reading emails.
One of the ways of improving your management of time is to write concisely. Saving more words means saving more time. Both for you the writer and for your reader.
Concise writing is not restricted to reports, journals and articles. It is as applicable for email and any other business correspondence.