While the application does not currently have the ability to drag-and-drop files directly from Outlook into the application directly, here is a quick trick to get files from your email into the application: 

  1. Open Outlook, File Explorer, and the application multi-file upload window. You may create a temp file in File Explorer to make it easy to locate your attachments pulled out of Outlook.
  2. Drag and drop the attachments from Outlook into the File Explorer window. 
  3. Grab the selected group of files from the File Explorer Window and drag them into the application's multi-upload window.