Capitalization in Email
Before you dispense with traditional capitalization, consider the reasons that capital letters exist. First, capital letters provide important information to the reader. When you capitalize a word, you indicate something about it. Perhaps it is the first word in a sentence; perhaps it is a proper noun such as John or Pepsi. In a business environment, where you want to convey the maximum amount of information in the minimum amount of time, standard capitalization can help ensure clarity in your writing.
Therefore, don’t underuse capital letters. It is especially risky to write people’s names in all lower-case letters, a practice that some could perceive as insulting. Particularly if you are writing to a person senior to you, use standard initial caps for his or her name, even if the person habitually lower-cases yours. The same goes for clients.
Don’t use all capital letters, either. Writing emails entirely in capital letters is widely perceived as the electronic equivalent of shouting. Many readers find this habit extremely irksome; heed your audience’s preferences.