> considering that many emails have embed HTML and would ideally use a modern web view to render correctly
It might be me, but i prefer them to be rendered incorrectly in a text-only view :-P. I use email since the 90s and so far i do not think i can come up with any case where the HTML in an email was actually useful and not used for fluff (which i do not mind but can do without), branding (which i do not care at all about) or -way way more often- advertisement.
Also almost all HTML mails i've seen come in text-only version too and any useful bits are attachments anyway.
It might be me, but i prefer them to be rendered incorrectly in a text-only view :-P. I use email since the 90s and so far i do not think i can come up with any case where the HTML in an email was actually useful and not used for fluff (which i do not mind but can do without), branding (which i do not care at all about) or -way way more often- advertisement.
Also almost all HTML mails i've seen come in text-only version too and any useful bits are attachments anyway.