Include your full name and email address in the body of every message. Many email programs help you to do this with a signature file. Use the subject line to provide a meaningful synopsis of your message, especially if you're sending business-related email or email to a stranger. Take a moment to delete extra lines and text from replies and forwards. Don't use email to criticize other people's grammar and spelling.
Email is informal and criticisms like that are called flames .
Remember that everyone makes mistakes. Always check your own email for readability and spelling. Double-check the email address of the person to whom you're sending your message.