I'm pretty sure this API doesn't run synchronously. You're not going to sit with a request open for hours (days?) waiting for the server to return data to you.
Email is maybe not ideal, but a lot of the other ways of returning results from an API asynchronously require clients to set up their own infrastructure (or pay to use someone else's), which might not be desirable for this particular API's users.
Email is maybe not ideal, but a lot of the other ways of returning results from an API asynchronously require clients to set up their own infrastructure (or pay to use someone else's), which might not be desirable for this particular API's users.