I have a 50 list of emails on my crm that has its own editor.
from the 50, there is about 3-5 templates that will look slightly different. I have the design i want in responsive. Amongst the new design layouts are Receipts, message, announcements, and invoices but with the same template.
I will access to the old html template and you will replace it with the new.
Also, you will edit from the editor to make each format is perfect designs.
Please make sure your repsonsive template works on all email providers such as gmail, yahoo, hotmail/outlook etc..