What happens if packages are returned?

The packages that are sent back are lost, we’ll not receive them back, so can’t resend them. Please provide the correct address.  If it was our mistake, we will replace it, but if the address that you provide was incorrect, we can not replace it.

How big should my P.O. Box be ?

It doesn’t matter.  UPS holds your package and you get a hold in your mailbox.  You would have to take the note and exchange for your package the UPS counter.  This goes the same for USPS as well