Short answer:
The Unknown Tenant error can occur when the Xink Outlook add-in is installed from Microsoft AppSource, but Azure AD / Microsoft Entra integration is not enabled for the tenant. A clean installation using the Xink Outlook add-in manifest is usually the recommended workaround when Entra integration cannot be enabled immediately.
The Unknown Tenant error means the Outlook add-in cannot correctly identify or connect to your Xink tenant during sign-in or add-in loading.
This is most often seen when the Outlook add-in was deployed using the AppSource version, but the required Azure AD / Microsoft Entra integration has not been enabled for your Xink account.
When does this happen?
This issue may occur when:
- The Xink Outlook add-in was deployed from Microsoft AppSource.
- Your Xink tenant does not have Azure AD / Microsoft Entra integration enabled.
- The add-in cannot map the signed-in Microsoft 365 user to the correct Xink tenant.
- The required Microsoft Entra approval or internal approval has not yet been completed by your organization.
Why does the Unknown Tenant error appear?
The AppSource version of the Xink Outlook add-in depends on Microsoft identity information to identify the tenant correctly.
If Azure AD / Microsoft Entra integration is not enabled, the add-in may not be able to determine which Xink tenant the user belongs to. As a result, Outlook may display an "Unknown Tenant" error.
This does not usually mean that the user, signature, or Outlook profile is broken. It normally means that the add-in deployment method and the tenant integration setup do not match.
Recommended solution
If Azure AD/Microsoft Entra integration cannot be enabled immediately, the recommended solution is to perform a clean installation using the Xink Outlook add-in manifest version rather than the AppSource version.
This allows the add-in to connect using the correct Xink configuration without waiting for your internal Microsoft Entra approval process.
What Xink Support may do
To help verify the updated deployment, Xink Support may:
- Provide or deploy the Outlook add-in using the manifest version.
- Rename the manifest, for example, to Xink V2, so administrators and users can confirm that the updated add-in has propagated.
- Add a test user or administrator under the Employees section in Xink so the add-in can be verified once the update is visible in Outlook.
How to verify the update
- Open Outlook.
- Check whether the updated add-in name appears, for example, Xink V2.
- Open the Xink Outlook add-in.
- Confirm that the Unknown Tenant error no longer appears.
- Confirm that your user is available in Xink under Employees.
- Test that the correct email signature is available or inserted as expected.
Propagation time
After the add-in has been updated or redeployed, Microsoft 365 propagation can take time.
In some environments, the updated Outlook add-in may appear quickly. In other environments, it may take up to 72 hours before all users see the updated add-in in Outlook.
During this period, some users may still see the old AppSource version while others already see the updated manifest version.
What administrators should check
- Confirm whether the add-in was deployed from Microsoft AppSource or by using a manifest file.
- Confirm whether Azure AD / Microsoft Entra integration is enabled in Xink.
- Check whether the updated manifest name, for example, Xink V2, appears in Outlook.
- Allow up to 72 hours for Microsoft 365 propagation.
- If the issue continues after propagation, contact Xink Support with screenshots of the add-in name and the error message.
Important note
The Unknown Tenant error is usually related to the add-in deployment method and Microsoft Entra tenant identification. It is not normally caused by the email signature template itself.
If your organization wants to continue using the AppSource version, Azure AD / Microsoft Entra integration may need to be reviewed and enabled according to your internal approval process.
