If use D/P as payment method, the exporter ships the goods, and then gives the documents (including the bill of lading necessary to claim the goods at the foreign port) to his bank, which will forward them to a bank in the buyer’s country, along with instructions on how to collect the money from the buyer. When the foreign bank receives the documents, they will contact the buyer and provide documents to the buyer only when the buyer pays. And the risk is mostly on the seller side.