Pound cakes are one of the best types of cake to ship due to the built in moistness of the cake. Bake the cake in a disposable aluminum pan so that the cake and pan can be mailed together. The pan serves as an extra defense against damage during shipping. Wait until the cake and pan have completely cooled before beginning the packing process. A light, pourable icing may be applied to the cake and allowed to cool before packing as it will help lock in moisture.
Wrap the pound cake with aluminum foil, pressing the foil as close to the cake as you can without damaging the surface.
Place the pound cake into a cake box just larger than the cake itself. Fill the gaps using eco foam for cushioning. Close up the cake box and use a piece of tape to seal it shut.
Place the entire cake box into a sturdy cardboard shipping box. Fill the gaps generously with eco foam. Close the box and seal it closed using packing tape. Write "perishable" on the top of the box.
Take the box to your local post office to acquire the appropriate label for sending. Ship overnight for the best chance that the cake will make it there intact and fresh for eating.