I've read countless threads about issues trying to vertically stack <td> tags for mobile, and in developing my email template i found that for whatever reason, using the <th> tag works everywhere that supports media queries.

I just convert the <td> tags that need to stack to a <th> (not valid...but, ya know we're in the email world here) and in my media query, display as block at 100% width (parent elements also at 100% width) and done, the th's stack vertically.

Just curious why i've read several Litmus articles that advise against using the <th> tag in general, and why all the <td> stacking woes i've read about don't use this method? Surely others have found and used?