Sounds like adding Universal email to the order success may be the best way forward to ensure the emails are sent.
Is there a guide to doing this? I found one for Universal email to update the email but this assumes that eCart has already utilised Universal email during the checkout creation.
If not, could you provide guidance? I would want the email to be sent to the customer and the business containing complete information including the customer contact details and order information.
I did have a look at adding Universal email but I am not sure which options to set and how to grab the various customer information fields and the order information.