I'm doing a PhD related to my supervisor's research area. Sometimes, I think about problems that I do not immediately know the answer to. Naturally, I come to Stack Exchange and other forums and ask :) But on some occasions, the question is rather specific so I email my supervisor instead.
How often do you generally email a supervisor about research questions? I know he has other PhD students plus his own research to do. I have a weekly 45 min meeting with him, so I try to save questions for that and give a report to him about what I did in the previous week. On very rare occasions, he comes down to the lab and we talk in person. I usually email him when there is some administrative stuff we need to talk about, but I'm asking about research questions here or about giving updates about the progress of my research.