I have many business units and I'd like to know via API if the BU is sending emails using Content builder or classic content. I know classic content uses SOAP API and Content builder REST API, but I don't seem to find a way to know via API how the emails are being created or sent. Any thoughts?
One option to do this would be to use the Job data view and check for the last month's sends. In there there is a field called email name. You can lookup this manually in Content Builder and see if the email is sent from there. I'm sure there is a way of doing it via API but I didn't find much time to investigate. I hope this helps someone down the road.