Is there any thunder stone wonder mail for Pokemon mystery dungeon explorer of sky?

Yes, there are two Wonder Mails containing a Thunder Stone in Pokémon Mystery Dungeon: Explorers of Sky. Both of them require a Pokémon that can learn Discharge.

- Wild Thunder: Use a Kecleon with Discharge (Lv.15) at 1-7F of Drenched Bluff (daytime)

- Thunderbolt Charge: Use a Starmie with Discharge (Lv.16) at Water's Edge