Yes, you can restrict user login to users from a specific email domain using Ory Actions. You can add extra validation that allows you to control exactly who can sign up. For example, you can prevent users from signing up when their email domain doesn't match a certain value. This way you can allow only users from certain organizations to sign up. You can use flow-interrupting webhooks to add this validation to sign-up and registration flows. For more information, you can read the [Flow-interrupting webhooks documentation](
https://www.ory.sh/docs/guides/integrate-with-ory-cloud-through-webhooks#flow-interrupting-webhooks). Also, you can use Ory Actions before events such as user login, registration, triggering account recovery or verification, and updating account settings. For example, you can enforce invite-only registration in your application by triggering an action that checks if certain criteria are met before the registration flow starts. This can be useful for controlling the number of users that have access to your application and ensuring that only authorized users can register. You can read more about this in the [Ory Actions documentation](
https://www.ory.sh/docs/kratos/hooks/configure-hooks#actions-triggered-before-events). Remember to carefully plan and communicate any changes to your users in advance to minimize disruption and maintain a seamless authentication experience.