Use mailcap to display (some) non-text content
The mailcap library can display content based on MIME type. See e.g. eww-display-pdf
for an example of how. This could replace custom code to display non-text types.
The mailcap library can display content based on MIME type. See e.g. eww-display-pdf
for an example of how. This could replace custom code to display non-text types.