Definition
A US federal law governing commercial email, requiring accurate sender details, a clear physical address, a working unsubscribe link, and non-deceptive subject lines.
Unlike some other regions, the US doesn't require prior opt-in for B2B cold email, which is what makes cold outreach legally viable there in the first place. But every message still needs an honest 'From' line and a real way to opt out, and violations carry real financial penalties per email.
Where this comes from
Read: Cold Email Compliance: CAN-SPAM, GDPR & DPDP