My T gave her email to me. I think it was because it would might be easier for me to tell things in an email instead of talking. And then we could talk about in session. I don't use it a lot. I'm afraid I will bother her too much. So I don't know how much email is actually allowed. I use it sometimes when I want to tell her something, but I'm too afraid to say it in session.
If a want to cancel or change an appointment, then I would use the Phone.
My T's emailaddress is a work email. When she started working at an other angency, she got a new email. I don't know if she still check that other email, just in case.

All the previous T's didn't had an email or if they had then they didn't gave it to me.