Pre-Stage Destination Folder

Is it possible to copy data to the DeltaCopy destination folder first before running an initial sync? Or will DeltaCopy delete the data and send all new files from the Source? The data I need sync'd resides over a slow wan link and is approx 30GB in size. I previously used Robocopy to sync and would like to prestage that old Robocopy data to the DeltaCopy destination folder in order to prevent all 30GB from being re-sent.

How does the software keep track of what has been sent and what deltas have changed --- does it do a real time comparison between files at the source and destination?

Thanks....