CAN-SPAM

Statute United States (with UK and Canadian equivalents)

CAN-SPAM, PECR and CASL are the rules under the send button. The American version is opt-out: you may email a stranger provided you identify yourself and honour an unsubscribe. The British and Canadian versions are opt-in: consent comes first, and CASL’s penalties are severe enough that most senders operate to it globally rather than maintain two systems.

• A working unsubscribe - Honoured within a fixed window, and the one obligation every regime in this family shares.
• Truthful routing and subject lines - Headers and subjects must not misrepresent origin or content.
• Identification and postal address - The sender must be reachable outside the channel used to send.
• Consent before sending, outside the US - PECR and CASL invert the default, which is why suppression state has to be portable.
• Liability that follows the list - Using a platform does not transfer the obligation; the sender remains responsible for the list it uploaded.

This family produces the single most under-published artifact in the marketing stack. Every obligation here is about state — who consented, who withdrew, who must never be contacted again — and that state has to be honoured across every platform a business integrated. The State of Marketing & Advertising APIs reads 2,925 specification documents from the 244 best-published companies in that market and finds suppression and preferences published as resources exactly zero times, and unsubscribe once. The compliance work is being done; it simply is not described anywhere a machine can read it.