In the KinzPost Office, you can send letters or packages with items inside to people on your friends list. There is a fee for this service. In the letters, you can put stickers, change the paper, and add various predetermined messages. In packages, you can send up to 3 items, and you are charged KinzCash for everything you send. You used to be able to send eCards based on Webkinz World.
Mail comes in two forms: letters and packages. Both require a fee to send, and can only be sent to friends.
Here is you what you see in your mail sometimes: