CAN-SPAM
The US federal law on commercial email, enforced by the FTC. It requires no prior consent but sets rules on honesty, identification, a postal address and opt-out.
What it means
The FTC's compliance guide lists the requirements: no false or misleading header information, no deceptive subject lines, identify the message as an ad, include a valid physical postal address, tell recipients how to opt out, honour opt-outs within 10 business days, and monitor what others do on your behalf, since both the company promoted and the one sending can be held responsible.
The law covers commercial messages, judged by their primary purpose, and makes no exception for business-to-business email. Transactional or relationship messages are exempt from most requirements. Each separate email in violation can bring civil penalties, and the guide lists aggravated practices such as harvesting addresses and dictionary attacks that can bring criminal penalties.
CAN-SPAM sets a floor: Gmail, Yahoo and Microsoft rules are stricter for bulk senders.
Related terms
On this site
Sources
What this definition rests on. The wording is ours; the facts are theirs.
All 432 terms in the glossaryThe wiki: blocklists and bounce codes