I realise that people here (including you) might not like my opinion but to me it seems that you are trying to manipulate him. If you would really want to terminate then you would have no problem doing that in session face to face and it would not be dependent on whether the T responds to the email or not.

In reality you are trying to control him. Instead of using what he is offering you, you are trying to move him to a place where he would do what you want him to do - respond to emails. Unfortunately, the treatment won't happen over emails and the only things that matter are the things that are happening in the session.

I know that many people here exchange emails with their T's and I have emailed to my T as well. But there are differences between email and email. Whereas with one person allowing emails might be necessary and useful, with another one it can be detrimental and not helpful to the treatment (even if sending the emails and receiving responses would feel good). In the end, the goal of the T is to help you and it is his professional judgement whether he thinks emailing is good for your treatment or not.

I think it also makes sense to point out that the T is not trying to control you. He is not forbidding you to email if that's what you want to do. It's totally up to you whether you decide to email him or not. But you want to control him and make him respond to you, even when he feels that it's not helpful.

I'm not saying that terminating would be wrong in this case. After all you and only you can decide whether you are ready and willing to face those things in yourself that the treatment draws out. It hasn't been said anywhere that everyone should even want to face these things and work to understand them. The fact is that you cannot run and hide from yourself forever but maybe it is easier for now. Wether the T will or will not respond to emails is not the point at all.