If you are trading a Pokémon to a friend and you wish to give them a message, you have the ability of attaching a mail to the Pokémon. The mail come in a variety of styles. In the original Gold & Silver games, you could manually write the mail and place anything you wanted on it. However, in later games, it got restricted to to a massive selection set phrases. The mail is all one-use only and if you remove it from a Pokémon, the mail gets sent to your in-game PC.

Picture	Name	Effect
	Air Mail	Stationery featuring a print of a steel suspension bridge. Let a Pokémon hold it for use.
	Bead Mail	A piece of MAIL to be held by a Pokémon. It will bear the print of the Pokémon holding it.
	Bloom Mail	Stationery designed for a thank-you note. Let a Pokémon hold it for delivery.
	BlueSky Mail	Sky-print MAIL.
	Brick Mail	Stationery featuring a print of an arched bridge. Let a Pokémon hold it for use.
	BridgeMail D
	BridgeMail M
	BridgeMail S
	BridgeMail T
	BridgeMail V
	Bubble Mail	Stationery designed for invitations. Let a Pokémon hold it for delivery.
	Dream Mail	A piece of MAIL to be held by a Pokémon. It will bear the print of the Pokémon holding it.
	Eon Mail	EEVEE-print MAIL
	Fab Mail	A piece of MAIL featuring a gorgeous, extravagant print. It is to be held by a Pokémon.
	Favored Mail
	Flame Mail	Stationery designed for writing about your favorite things. Let a Pokémon hold it for delivery.
	Flower Mail	Flower-print MAIL
	Glitter Mail	A piece of MAIL featuring a cute PIKACHU print. It is to be held by a Pokémon.
	Grass Mail	Stationery designed for introductory greetings. Let a Pokémon hold it for delivery.
	Greet Mail
	Harbor Mail	A piece of MAIL featuring a cute WINGULL print. It is to be held by a Pokémon.
	Heart Mail	Stationery designed for writing a reply. Let a Pokémon hold it for delivery.
	Inquiry Mail
	Like Mail
	LiteBlue Mail	DRATINI-print MAIL
	Lovely Mail	Heart-print MAIL
	Mech Mail	A piece of MAIL featuring a cute MAGNEMITE print. It is to be held by a Pokémon.
	Mirage Mail	MEW-print MAIL
	Morph Mail	DITTO-print MAIL
	Mosaic Mail	Stationery featuring a print of a brick bridge. Let a Pokémon hold it for use.
	Music Mail	NATU-print MAIL.
	Orange Mail	A piece of MAIL featuring a cute ZIGZAGOON print. It is to be held by a Pokémon.
	Portrait Mail	MAIL featuring the holder's likeness.
	RSVP Mail
	Reply Mail
	Retro Mail	A piece of MAIL featuring a print of three cute Pokémon. It is to be held by a Pokémon.
	Shadow Mail	A piece of MAIL featuring a cute DUSKULL print. It is to be held by a Pokémon.
	Snow Mail	Stationery featuring a print of a sky-piercing bridge. Let a Pokémon hold it for use.
	Space Mail	Stationery featuring a print of a red drawbridge. Let a Pokémon hold it for use.
	Steel Mail	Stationery designed for writing recommendations. Let a Pokémon hold it for delivery.
	Surf Mail	LAPRAS-print MAIL
	Thanks Mail
	Tropic Mail	A piece of MAIL featuring a cute BELLOSSOM print. It is to be held by a Pokémon.
	Tunnel Mail	Stationery designed for writing questions. Let a Pokémon hold it for delivery.
	Wave Mail	A piece of MAIL featuring a cute WAILMER print. It is to be held by a Pokémon.
	Wood Mail	A piece of MAIL featuring a cute SLAKOTH print. It is to be held by a Pokémon.