I'd prefer the manager getting up and tapping me on the shoulder even if that is more distracting. Then at whatever review you might have (or not) say that constant interruptions have a negative affect on the work you do. Your manager sounds like a bad one.
I don't want to heap the blame entirely on him. Other people I work with also hold the opinion that emails should be responded to as soon as possible, so he has support. It's all relative, and they certainly pay me well enough for the trouble.
Sometimes yes, sometimes no. Distraction factor also counts. My comment was probably a little arrogant though. The reason I said I'd prefer that was so that the manager would have to expend effort to get an answer immediately, to offset my own distraction. "If I have to be distracted then I'm taking you down with me" kind of thing.
