When attempting to update a recipient's email address via the API, I am receiving a HTML 400: Bad Request error as a response. I am able to update all other fields/attributes for a recipient record, just not that one. I am aware of the note in the API documentation that indicates the email field can only be updated using a PUT request. I have attempted to make the change using both the EmmaPython wrapper module and by hand-crafting a PUT request via the python request module. In either case, I receive the 400 error.