What error message are you getting?
You mention customs, so I am assuming this means your order has an international destination. Often the problem lays in the buyer name or address with hidden keyboard characters that do not transfer to Western or with an address that the Pitney Bowes/Paypal or Canada Post platform cannot comprehend. I recently had a destination in Austria that was summarily rejected despite being correct because, like Holland, the street comes first and number second.
