If Individual Message is enabled, the corresponding tab will be displayed on the Order Edit page and Customer Edit page, as shown in the image below.
The image below shows the individual message form for a customer from the administrator panel in nopCommerce. You can send individual messages to customers from two locations:
Customers → Customers → Edit (select any customer for edit) → Send message (tab).
Sales → Orders → View (select any order to view) → Send message (tab).
If Private Message is enabled, you can also send the same message as a private message to the customer.
