Configure email-domain signup protection
Open **Settings → Registration → Signup Protection**. You need permission to save registration preferences. This policy is evaluated for the email used during new registration.
Select an action
- **Off:** disables disposable-domain matching.
- **Flag only:** allows a matching signup and adds an internal review flag.
- **Manual approval:** leaves a matching account pending review.
- **Block registration:** rejects a matching signup.
**Blocked Email Domains** follows the selected action. Merely adding a domain there does not make Flag only or Off behave like Block registration.
Allowed Email Domains
A nonempty allow-list restricts registration to matching email domains. Allowed matches are checked first; other domains are rejected. Use domain names rather than full email addresses. If you want ordinary public registration, do not fill this with only your own business domain unless you intend to restrict signup to that domain.
Blocked Email Domains
Enter domains you want handled by the selected protection action. The policy also includes known disposable domains. Save, reopen the settings, and test one permitted and one restricted address under the intended action. Keep testing to accounts you control.
Unexpected rejection
Check the allow-list first, then the selected protection action and custom blocked domains. A customer can use a valid email provider yet still be rejected by your workspace allow-list. Confirm the intended rule before changing it; ask support to inspect the error if the saved policy and result still differ.