The shipper if an ffl dealer it is required to have a copy of the ffl that they are shipping to
There is no requirement that either FFL RETAINS any license copy, however. Once you record the name and license number of the other FFL in your A&D book you can feed his license copy directly to the shredder. (Or you could just look him up on EZ Check and swear on John Browning's grave that you saw a certified copy. Nobody is going to know the difference.)
If you are an individual and sending a gun out of state you must verify that the receiver is licensed
And they can verify the status of the FFL by using EZ Check.