CAN-SPAM
CAN-SPAM is the U.S. law for commercial email: accurate headers, honest subject lines, a postal address, and a working opt-out honored within 10 business days.
CAN-SPAM is the U.S. law for commercial email, enforced by the Federal Trade Commission (FTC). This summary follows the FTC’s CAN-SPAM compliance guide and is not legal advice.
It covers any message whose primary purpose is advertising or promoting a commercial product or service, including business-to-business email. It is not limited to bulk sending.
Commercial email requirements
Accurate From, To, Reply-To and routing information.
No deceptive subject lines.
Clear identification as an ad.
A valid physical postal address.
A clear opt-out method that works for at least 30 days after sending.
Opt-outs honored within 10 business days.
Hiring a vendor does not transfer responsibility. Both the promoted company and the sending company may be liable.
Transactional and relationship messages
Messages whose primary purpose is transactional or relationship (receipts, warranty or security notices, account-status changes) are exempt from most provisions but may not use false routing information. A mixed message is commercial if the subject line reads as promotional or the transactional content is not mainly at the beginning.
Related: CASL, Transactional emails, Opt-out (or Unsubscribe).