Initiates the creation of the file with data about emails that matched the search query. When the file is created, it will be available for download. On the successful call, returns the unique identifier that represents the file creation process. The file creation is an asynchronous process because the amount of data that should be exported to the file and the export duration is hard to predict. The call to this endpoint just initiates the file creation. To check the file status and get the download link, send a GET request to the /v4/data/account/downloads/ API endpoint with the identifier returned by this endpoint. The number of rows available for download is determined by the subscription plan.