I solved exactly that problem I and I sell it to those willing: https://race-term.com
It is multiplexer so survives app kills, and interface is heavily keyboard driven.
I tried running email in it though resigned (and guess what, wrote my own) because HTML email support is must have nowadays.
"... because HTML email support is must have nowadays ..."
I don't find this to be the case.
I use (al)pine exclusively and with only three or four hacks/workarounds manage a normal, modern email workflow.
Unlike SMS where my unix-based telecom results in green bubbles, in the email world there is not even that small indication that anything is different on my end ...
This is the digital equivalent of having a mess of papers sprawled on your desk.
What a messy thing to do. Maybe fine for a project but a desktop? No.