We have email editor 2.0 turned on, but still have this issue of mobile rendering shrunken to the point where text is illegible. Technically, we "broke" an email starter template because we edited code (shape and location of text boxes), but different sections/modules of templates render with ~66% width that they should. Anyone have a way to fix the modules rendering incorrectly with their width size on mobile?
There's several different things that could be causing this, but most likely you have a table or table cell over-extending as a result of your move. Open the email up as a web page in Chrome and see what parts are over by highlighting sections in Inspector.
Honestly, this is very complex and there is no recipe we can give that would save your day. Usually, when the template is broken, the simplest way is to start over from the original one. A big advice to give to anyone who starts playing with email templates in Marketo: always backup your previous version outside of Marketo.