I haven't done it very often, but the few times I haven't answered all off the questions in an email has been because some of the questions are a waste of time. I had an engineer recently ask me if I could move the location of where I was running a pipe through a floor grating. Changing the location would have changed nothing, made my job more difficult, and would have been a tripping hazard. All off this could have been avoided if they had gotten or from behind their desk and just gone and looked at what I was working on in person. I ignored their question and sent more pictures of the area. They finally said that I was good to proceed with my original plan.