Be very careful using this service. They are suppose to act as a broker between individuals and companies that have used boxes and those who want them. After you place the order you will receive an order confirmation, and are suppose to at some later time receive the contact information where to pick up the boxes (they only provide a general location when you place the order).
No additional emails were ever received, their address was white listed (per the original email received), so there was no issue with spam filters. They also claim to have called, but phone records show otherwise.
They claim it is the buyers responsibility to track down any unreceived emails or they will charge a missed pickup fee and cancellation fee. Fortunately in my case the purchase was small because I was testing the system before placing the large order we wanted and they did refund the money when a dispute was filed with paypal. (We particularly wanted to test the system because they don't show actual pictures of the used boxes, just of new boxes that are roughly the same size as the used boxes. Depending on the markings on the boxes we may or may not have been able to use them and didn't want to spend thousands gambling on them.)
So, they may provide a useful service, but their email can be unreliable and it's the BUYERS responsibility to make sure their email system works. If you chose to use this system be sure to dispute orders when you don't receive the 'pickup location/date' email quickly. The confirmation email is not enough to verify you will receive your order.
There are more reliable services out there (so we found out).