If you are communicating inauthentically (you need to suppress emotions not appropriate for an interaction), on average, it is best to utilize telephone or audio communication in order to appear most authentic.
If you have to use email to relay emotions that you want to be perceived as authentic, find a way to make it clear that you didn’t make the choice on purpose, or that the choice was for a positive reason, to help reduce the attribution that it was a low effort.
