The Mailbox contains items and frogs that have been either purchased, discovered [in pond/daily presents], or received [from other players]. These include the following:
- Frogs purchased from the FrogMart.
- Frogs ordered from the user's Catalog.
- Frogs cloned with the Froggydex.
- Habitats purchased from the Supply Shop.
- Scenery purchased from the Supply Shop.
- Frogs, habitats, and scenery discovered in daily gifts.
- Frogs, habitats, and scenery discovered on The Pond.
- Gifts (including frogs or scenery) from other players.
- Frogs obtained via a Special Event.
The Mailbox can hold up to 8 items at one time. The time an item or frog takes to be delivered varies with the level of rarity. When an item is first shipped, it shows in the mailbox with a delivery time which counts down in real time. You can instantly deliver or receive an item by using stamps, if you have enough stamps. The number of stamps needed to deliver an item corresponds with the amount of time left before delivery: 4 hours per stamp. Once an item or frog has arrived it remains in the mailbox (using one of the item slots) until you place it in a habitat or remove it.
The Express Mailbox is an in-app purchase that reduces all future delivery times by half. It can be purchased in the Pro Shop for $4.99.