There is not much to the art of the email; there are no great e-mail writers. I'd suggest learning to write long form instead. If it is purely about discipline you'd be better off exercising daily, and improving your diet over the coming year.
If you do not have a long list of things to say, what good is going to come of this except to LLM companies?
I think it would be useful if at least the first email could be read without a subscription. Just to understand the content, tone of voice, and so on. I believe the conversion rate would be higher after that first read.
Why not just write a blog? Why do emails need to be collected?