I am wondering if any definitive documentation exists for best practices in generating responsive emails. There have been several posts about this, but many are old, "assumed answered", and no responses really answer the question - they just link to third party Launchpoint solutions and templates. Templates are not helpful in my opinion, because it is very difficult to learn why and how things are constructed by just copying someone's code and trying to modify it.
As Marketo users are increasingly dependent upon designing mobile-friendly emails, I would hope that it could be in the plans for Marketo to provide some clear documentation on this. For instance, what is the importance of the body[yahoo] code that came with our pre-built default email templates?