An Act to promote the efficiency and adaptability of the Canadian economy (Canada's Anti-Spam Legislation)

Widely described as the strictest anti-spam regime in the world, and it is a genuinely separate exposure from PIPEDA. CASL prohibits sending a commercial electronic message to an electronic address without the recipient's consent, and the default is EXPRESS consent — a positive act by the recipient — with implied consent available only in defined circumstances such as an existing business relationship, each with its own expiry. Every message must also identify the sender and carry a working unsubscribe mechanism honoured within ten business days. CASL separately prohibits installing a computer program on another person's device without consent, and altering transmission data. The CRTC can impose administrative monetary penalties of up to CAD 1 million per violation for an individual and CAD 10 million for an organization. A US-style opt-out email program lawful under CAN-SPAM is not lawful in Canada, which is the single most common compliance failure here.