sunny, what a nice thing for him to do, sending you a meaningful email.

What about replying like you would like to, then adding that you would like to continue talking about it next session?

I hope you'll tell him too about what you are saying and feeling about the billing and your worry about him taking time to email when he doesn't get paid for it.

I think some "extras" are including in our fees. A phone call here and there, an email, a few extra minutes once in a while. I think the fee is more global to include those kinds of things.