Email and Reflow at 320 CSS px

I am wondering when any email client will start to comply with WCAG 2.1
1.4.10. We are about to approve WCAG 2.2, and not one major player can
manage 640 CSS px let alone the required 320. It is disgusting.

I am not greedy, everything doesn't have to be perfect, but the content of
email messages falls squarely within the scope of 1.4.10. Why is every
major provider so recalcitrant?

From the user perspective email is a heavy reading load. It is pure text
reading. Users need reflow to keep up.

I will send this out to the list, and to read any responses I will have to:

   1. Copy the HTML of the message.
   2. Paste it into my IDE.
   3. Run my page in a browser.

That is a lot of work to read email.

Best, Wayne Dick