This article clarifies whether the Organization Domains feature restricts access to configured email domains.

• Organization Domains
• Organizations

The Organization Domains feature is intended for organization discovery. This helps direct users to the correct organization based on their email domain during the pre-login prompt. It does not restrict sign-up or sign-in once the user reaches the organization's sign-in screen. The users can use any email domain at that point.

If a strict email domain association is required for sign-in within an organization, implement a post-login action.