Answer: You can't hear the tone of voice or get clues from body language.
Explanation:
When sending emails, the sender and the recipient communicate through a screen, thus each person is unable to see the other when conversing or hear the inflections or emphasis of voice in the message, although we can always attempt to interpret tone. Email allows you to store emails in the inbox or archive and access sent messages, but email lacks the ability to intimately understand specifics such as tone of voice or body language.