If you attempt to install an Office add-in to a domain that doesn't seem familiar, it’s possible that there might be a risk to your security. In order to help us protect you, we ask that you review and verify that the domain you want to try to install the add-in to is your organization's domain.
If you trust the domain you’re being asked about and recognize it as your organization’s domain click Back and then click or tap Yes to install the add-in. If you don't recognize the domain, then follow these instructions to install the add-in into your organization’s domain.
