Mirror Mail is a Normal Trap Card.
Trap Cards are normally Set first and can be activated on a later turn, often in response to an action.
On the current TCG and OCG Forbidden & Limited lists tracked here, Mirror Mail is Unlimited.
YGOPRODeck lists Mirror Mail for these formats: Duel Links, Common Charity, TCG, OCG, Master Duel.
A listed print of Mirror Mail appears in Photon Shockwave (PHSW-EN067) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Mirror Mail is about $0.08 on TCGPlayer (prices change frequently).
