Infected Mail is a Continuous Spell Card.
Spell Cards are usually activated from the hand on your turn unless their type gives another timing window.
On the current TCG and OCG Forbidden & Limited lists tracked here, Infected Mail is Unlimited.
YGOPRODeck lists Infected Mail for these formats: Duel Links, Common Charity, TCG, OCG, Master Duel.
A listed print of Infected Mail appears in Battle Pack: Epic Dawn (BP01-EN085) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Infected Mail is about $0.10 on Cardmarket (prices change frequently).
