I usually respond to all, but I am guilty of having done this when I really needed a mental health break and I think that's fine. Adulting is okay as long as you have the bandwidth to adult, not when you are crumbling from all the stress. I realized that once you make your boundaries clear, people give you that space. When I would tell people, "No, I can't take calls, I am not well", I actually meant it then and I am glad I did.