My T gave me permission to use email between sessions. In doing so, she never committed her to providing replies, but she does print them out so we can discuss them during the next session. She has been good about replying when I indicate I would like a reply. I think she has made it pretty clear that email, is not something she wants me to depend on, but she has accepted that it is the only way that I can sometimes get stuff out. This option has been very important in my therapy--from my perspective.