How do I save an attachment to a local folder in VMware Boxer email client?

I have recently begun using VMware Boxer email client for Android. I received a PDF attachment to an email. When trying to download it, I am given only two options: "Open in" and "Save in Boxer." When I save the file in Boxer, it is not visible anywhere except in the Boxer file browser. I have looked through the directory structure with another file browser, but I do not see where the file is stored on my phone or even where Boxer stores its data. Does anyone know how I can simply save the PDF into my "Downloads" directory and not be stuck with it within Boxer. I had been using Outlook, and it by default just stores the downloaded file in the public downloads directory.