How about Google pushes the industry to standardise the HTML and CSS allowed (or not) in an email?
Then EVERYONE sending an email can make sure it's formatted to convey the message on whatever device displays it.
If email really still is relevant (and I think it is), then why the fuck this hasn't been done long ago, I just can't fathom.
Browsers are now, by and large, accurate and consistent, why not the same for email renderers?