The attached Excel file lists how Enable determines where to send the order confirmation and shipping confirmation emails.
Enable will generally attempt to use the per-sales-order ship-to and bill-to emails, if they are present on an order. For online orders, Enable will initially fill in those fields based on specific rules as outlined in the attached Excel file.
For offline orders, the per-sales-order contact fields are filled in as part of the sales order entry / maintenance process.
If at the time of sending out the confirmations, the per-sales-order contact fields are missing, specific fallback values are used in some cases, as indicated in the attached Excel file.