When answering emails, you should also pay attention to the tone of the email itself.
Let’s see some category examples:
. plain or funny. Joking by email, in my experience, is ALWAYS a NO NO. In any case I wouldn’t suggest answering with a ‘yes’ or ‘no’ to an email in which the sender is trying to be funny or relaxed or something. He can be rude.
. angry or calm. Emails shouldn’t be interpreted. In general the tone in an email is by far different from what you can feel on a face-to-face communication. Usually the tone is HIGHER in an email: no matter if it’s positive or negative. For this reason I suggest to be always some degrees more ‘plain’ than the original mail you are answering.