Wasn't a big fan of this post. it would have been more interesting if he showed some examples of his three sentence replies to actual emails. 3 sentence emails sound great in theory, but really after a while if you are sending such short responses you are just an email mass producing factory.
I've been on the receiving end of some short/terse emails and I have to say that my impression is not positive. I understand people are busy, but when I read short replies to emails that don't make sense it doesn't make me feel special at all :(