You receive this email only when you have set up an external sharing review policy within the app.
An external sharing review lasts for fourteen days from the day it started, meaning that entrusted group owners have fourteen days to review and validate the links in their groups. Owners will receive the first notification at the start of the policy, followed by a reminder seven days later if they haven't completed the review for all their groups.
The email is triggered when a external sharing review is completed. A review is mark as completed if fourteen days have passed after the start of the review or if all groups owners have completed the reviews of all their groups.