https://support.box.com/hc/en-us/articles/4404822772755
According to the URL above,
"Box sends email notifications to the owner and any co-owners of the corresponding folder. Box only notifies co-owners who are directly collaborating on items with a pending expiration. Box does not notify co-owners who are collaborating via inherited permissions."

We would like Box to send alert emails to co-owners for folders (files) in the second tier and below.