Jake - Yep, there are always going to be edge cases in email to work around—especially if you’re in enterprise or education. Lot’s of outdated and random clients floating around out there.
Adam - Email on Acid has a great blog post on this issue. Check it out.
David - Anna is the best! Definitely my Sensei, as well. I would absolutely recommend her RED video to anyone interested in responsive email design. And you’re absolutely correct that what we typically report on emailclientmarketshare.com is not the case for everyone. Every industry, business, and list is different. The most important job for any email designer is knowing your audience and tailoring your content and design accordingly.