Email etiquette is important for professionalism, efficiency, and liability protection. Some key points of email etiquette include using a professional greeting and sign-off, having an informative subject line, using standard fonts and sizes, sending attachments in openable formats, proofreading for spelling and grammar mistakes, and responding to emails in a timely manner within 24-48 hours. Emails should be concise and avoid unprofessional elements like ALL CAPS, excessive punctuation or abbreviations, and private messages should be treated as such.