Business emails have to be professional therefore, the writer cannot write everything in capital letters. You should format it correctly and use paragraphs when you have a new idea. Don't repeat your point. Make sure the wording makes sense, so read it over before you send it. You should not use text talk in your emails. The reader won't understand what you are trying to say and it is not professional. Also, do not mark the email as urgent if its really not that important. It will waist the readers time.