To help with sorting my files I use Hazel. Hazel can be set up to watch folders, like your “Awaiting Filing” folder and then runs preset rules on that folder. For example, each of my client’s has a rule in Hazel which says that if Hazel finds a file whose contents have that client’s name in it, move that file to the client’s folder. This way as mail comes in, Hazel sorts the mail and places it into the client’s folder-it may not be in the correct sub-folder within the client’s virtual casefile, but it has at least made it into main folder.