In a marketing action, it is possible to edit / modify an HTML via CRM 360 ° or via a professional editor (with the same tools as Windows)
Editing a Template is not the same depending on your HTML. Indeed if your HTML is an imported HTML (therefore an HTML pro) the modification is the following (Cf. Edit / modify an HTML template (pro)).
The modification of a Template that you created via CRM360 ° is as follows (Cf. Edit / Modify an HTML template CRM360 )