Is drop shipping permissible or impermissible, taking into account an agreement with the original merchant, a description of the product, the possibility of returning it, and the setting of a delivery date?

This transaction can be structured according to the conditions of a forward sale (bay' al-salam), if the questioner buys the commodity for himself and then authorizes the merchant to ship it directly to the buyer. If this is not possible, the transaction can be structured through an agency (wakalah) for a fee, either for the merchant or the buyer.