This email is sent to users when we do a check and no longer see you pointing to Cloudflare's nameservers for the domain. Causes:
1. You moved away from Cloudflare's nameservers.
2. You have additional nameservers in the fields at your registrar. Only the Cloudflare nameservers you were assigned can be active at your registrar.
How to solve:
Change back to the Cloudflare nameservers in the email.