sys (abbreviation for System) was an automatic Club Penguin bot which was responsible for automatic bans, postcards "sent" by puffles, and postcards sent out to mark events. sys used the alias "Club Penguin" for postcards, as evident in specific postcards sent to players. On some postcards (such as the Welcome to Club Penguin postcard), the alias "Club Penguin Team" was used instead of "Club Penguin".
If the player tried to delete a postcard from sys, it would say "Are you sure you want to recycle this postcard from Club Penguin?" as if sys did not send it.