Unless if I've completely missed it, I'm trying to use the mailbox to transfer items from my old save (0.8)/a sandbox file in 0.9 then changing the save file from sandbox to story to allow the transfer onto my new save; except in either case, the items do not appear and act like I haven't deposited them into the mailbox even after saving. Am I doing something incorrectly compared to on 0.8, or is it just not available for now?