The response is OK, but the result of the information does not show it. Is it possible that because the object has name properties, the result is not displayed?
I reproduced the issue, but I am not quite sure if it is a bug or a limitation of "flattening" the object. Please open a support case so that this can be researched / prioritized / fixed.
As a note, if you are trying to retrieve only the list/array of emails from your result, you can also use the following to avoid the issue with "properties" attribute name.
I am starting to think that this is a bug in the test mode UI, not in the actual data action behavior. Could you see if your action works correctly in the end tool, like architect?
So this is a known issue, PCADMIN-7745. The test UI doesn't correctly handle having an object named "properties" in the results. I expect that means that your action was working, just not showing correct results in test mode. I noted that another customer had run into this issue on the ticket.
Thank you for letting me know that this is also an issue with Architect, that got me to look in the right direction and find the underlying problem. I have opened up a ticket for an issue in the backend service, BPIVR-2719.
In order to get your data action working I would recommend going with Jerome's approach to avoid having a "properties" object inside of your output schema.