Highlight your “Production” folder from your folder list.
Right-click on the “Production” folder, and click Export.
Read this part carefully: The “export” feature will place a folder on your Desktop, which will be named after the highest-level folder containing the “Production” subfolder. The fastest way to find the .mbox you need is to open a Finder window, navigate to your Desktop, and sort by “Date Modified” to find the most recent folder. Open that folder and each subfolder until you get to an icon that looks like an inbox named “Production.mbox” This is actually a folder. Double-click on it to open it.
Inside the “Production.mbox” folder (that looks like an inbox) you will find a file called “mbox” with no extension or anything. This “mbox” file is the one to drop onto the Discovery Genie target.