Post Office
From PinataIsland.info, the Viva Piñata wiki
Fanny Franker's Post Office is where you can retrieve messages, or buy crates to place in your garden. You can then pack up to five items, including pinatas, helpers, accessories, plants, fences, or other garden objects, and send them to anyone on your friends list via Xbox Live.
You can only pack one kind of object in a single crate. You can even pack up a sour pinata and ship it off to an enemy. The recipient can't tell what's in a crate until they open it.
