From https://amp.dev/about/email
> Embedding AMP within an email [...] add a MIME part with a content type of text/x-amp-html. It should live alongside the existing text/html or text/plain parts. This ensures that the email message works on all clients
You can be SURE that most of these AMP "rich" email won't have text/plain nor a text/html useful content
Can we hope for email providers to reject every AMP "riches" emails? Or will Google also take control of our inboxes?