I use this script to mirror a drive, and it only transfers files that are changed/new. So it can help save bandwidth/time if you are using a slow link/connection.
1) Download robocopy and place it in the correct directory (by default windows 7 and 8 can skip this step)
2) create a .bat file and put these contents in:
robocopy E:\ “\\server\j” /MIR /E
3) There you go, just double click it!