Duplicate emails in WLM, how to not copy into file folder

Hello, I have stopped the flow of emails!  I do however need to resort through my inbox(es) to move or remove the emails accordingly.  Some are older and in file folders already, copied from my previous operating system, but others are not yet in a folder.  My question is this:  Is it possible, from the in box, to place ONLY the new emails into their storage folders and not allow the duplicates to go as well?  If I just highlight and drag the whole bunch of any one group, the new and the old both go over to storage.  This leaves me with some duplicates (and in some cases a lot of duplicates.)  In moving regular files we have the chance to decide what to do with duplicates, copy erase or keep both or do nothing and skip--but I am not sure if there is a way to do this with emails.  Thank you in advance for your help and have a wonderful holiday season!  Bruce