Mail was introduced in Generation II. A message can be written on it and then given to a Pokémon to hold for delivery. It's most commonly used to send messages to other trainers via trading. Sometimes, mail appears in your PC from non-playable characters. There are many different designs available, and it can be bought at the majority of Poké Marts for 50 Pokédollars.
(Redirected from Retro Mail)