Although little smiley faces might tell the reader you were joking, they create their own bad impressions. Consider the circulation . The wrong choice could embarrass you. Unmark changes . Remove the hidden historical traces before you e-mail the document.
Many people prefer e-mail over any other communications medium.
Others think they get too much e-mail. Some people are telephone people. Others prefer paper. For some messages, e-mail isn't the best medium. Ask which medium works best for each recipient and for each situation.