We don't provide any built in function for automated response messages. It's possible for a programmer to design their own bot than can do it, and I've heard of some vendors doing just that. But other then that I don't have any info on the subject. As for the bond, the refund is a reward for vendors who prove themselves to be a valuable asset to the marketplace. The ONLY way to earn that refund is to meet the requirements laid out in the wiki. If you don't make any sales and close up shop, you forfeit the vendor bond.