WC Vendors Pro adds a new feature that allows customer mark orders received in version 1.7.0. This is enabled by default will work without any configuration.
For the orders which contain products from multiple vendors, when customer click on Mark received button, they will be directed to the order detail page where they can mark products received for each vendor. The products are grouped by vendors.
After a customer mark the order received, the order status will be set to Completed. The corresponding vendor order will have Received status in the Dashboard > Orders.
Setup the email
By default, an email will be sent out in seventh days after the vendor mark order received. You can customize this behavior in WooCommerce > Settings > Emails > Customer Mark Received. You can also change the email subject and email heading here.
The reminder email will be scheduled to send only if the vendor mark order shipped.