In the AcademyOcean Security Center, you can restrict access to your Academy only to users whose email addresses belong to specific domains:
https://app.academyocean.com/account/settings/academy/security
After enabling this feature, only users with email addresses from the allowed domains will be able to access the Academy. All other domains will be blocked from logging in.
If there are already learners in the Academy with other domains, they will lose access once this feature is activated.