My boss is not good with emails. There is often a mismatch between what he intends to say and how it is perceived by the recipient. His emails are often terse, negative and cold (even if he intended the words to be positive). He is so much better face to face.
I had a meeting with him last week and brought up the issue about the tone of his emails. He reckons it might be cultural as several senior colleagues have already been on his back about his email manner. I suggested he uses emoticons to make his intent clearer.