Postcards

Postcards are cards that can always be sent to other players, and bought for 10 coins each, in the Post Card Catalog. The categories for post cards are invitations and encouragements. Some post cards are related to Club Penguin ' s theme for the month. Other invitations include the Pizza Parlor, the Coffee Shop, the Dance Club, the Snow Forts, the Ice Rink, Sled Racing, the Ski Lodge, Mancala, Cove, and Find Four. New post cards come out at least every two months. Since Penguin Mail was introduced, people can save their mail inside a "mailbox" and receive it even when they're offline.

Trivia

 * It is impossible to retrieve a postcard if it has been deleted
 * The "Get Well" postcard was removed since some penguins kept on spamming each other in an insulting manner and penguins do not get sick as it is only a game.
 * Before the Penguin Mail had opened, the envelope button was a buddy request and the rectangle smiley face button was a postcard.
 * Puffles are able to send Postcards to you if they are hungry or have run away, but it is uncertain how they do it. Some think it is because they have telekenesis.
 * The Club Penguin Team is able to automatically send you postcards of important events.
 * Starting from May 1 2009, penguins are able to receive a 'check' monthly by being a Secret Agent or a Tour Guide. They will have 250 coins automatically added to their accounts. This is stacked up, so if you were a secret agent and tour guide, you would get 500 coins, 250 for each for job combined.
 * It is impossible to get more than 92 postcards. If you get 93, the latest postcard will be deleted and you'll still have 92.
 * Postcard were used to help express opinions during the 2009 Color Vote.
 * Only three postcards have free items in them: the Penguin Mail Postcard (sent by Club Penguin in July 2008, and the Merry Christmas Gift card that contained a blue sleeping cap with a bell.The other was Springy Santa Hat in 2011.
 * The 'penguin name' aspect of postcards is in text format rather than being part of the picture due to it being a variable.
 * Penguins that weren't Secret Agents can still join the Elite Penguin Force by receiving a special postcard from an EPF agent.
 * Non-Members can only have up to 50 postcards, however Club Penguin can add more.

Glitch(es)

 * There is a glitch, that, sometimes the name of the postcards are sent by the name "sys" or "undefined".