Each communication channel has a specific audience you are trying to reach. Knowing who that audience is and how to best communicate with them on their own level will do much to improve the relation and retention of information. When working as a manger it is important to think about the language and style before you write.
Language: Words are symbols. Each group of people have specific symbols which are often unique to their backgrounds. For example, employees of a particular company share a history embedded into their organization. They may not always be aware of it but it determines how "commerce" and interaction are conducted in that environment.
Using language (symbols) that relate to them help to ensure the essence of the message is better received. Each person will interpret that message and having it relate specifically to your audience improves upon the information transference.
Style: Tone and style help determine the overall intent and meaning of the words (symbols) being used. For example, a firm that hires highly educated engineers are likely to resonate more with longer paragraphs and detailed information than one which hires factory employees.
Furthermore, one should consider the speed of information and how the sentences are constructed to ensure the right tone is created. It is possible to have a statement that is positive be negatively received if the tone and style are not in alignment with the message.