Orange Mail appears in 3 version groups since Generation III, an All mail item in the Mail pocket

Effect, in PokéAPI's words

Orange Mail: “Lets a Trainer write a message and send it via Pokémon trade.”

Orange Mail shares its longer effect text with 35 other All mail items; it is quoted once on the category page. All mail

Games

Orange Mail is listed in the text of 3 version groups, first in Generation III

Game index by generation

Named in