When restricted email notifications are enabled in an organization, members can only receive email notifications about organization activity at an email address associated with the organization's verified domain. For more information, see "Verifying your organization's domain."
Outside collaborators are not subject to restrictions on email notifications for verified domains. For more information on outside collaborators, see "Permission levels for an organization."
- In the top right corner of GitHub, click your profile photo, then click Your profile.

- On the left side of your profile page, under "Organizations", click the icon for your organization.

- Under your organization name, click Settings.

- In the left sidebar, click Verified domains.

- Under "Enforcement preferences", select Restrict email notifications to domain email.

- Click Save.