Anti-spam law
Laws that regulate unsolicited commercial email, such as CAN-SPAM in the US, CASL in Canada and the ePrivacy rules in the EU and UK. They apply by where recipients are.
What it means
The major laws take two approaches. Opt-in laws require consent before marketing email: the EU's ePrivacy Directive (for individuals, with the soft opt-in exception), the UK's PECR and Canada's CASL, which also accepts implied consent in defined cases. Opt-out laws allow the first message but regulate its content and require an unsubscribe: the US CAN-SPAM Act, which covers B2B mail too.
Most share core duties: identify the sender honestly, avoid deceptive headers and subject lines, provide a working unsubscribe and honour it promptly. Data protection law (the GDPR in the EU) applies alongside them whenever addresses identify people.
Anti-spam law sets what is legal; mailbox provider rules decide what is delivered, and they are often stricter.
Related terms
On this site
Sources
What this definition rests on. The wording is ours; the facts are theirs.
- FTC: CAN-SPAM Act, a compliance guide for businessftc.gov
- Justice Laws Website: Canada's anti-spam legislation (S.C. 2010, c. 23)laws-lois.justice.gc.ca
- EUR-Lex: Directive 2002/58/EC (ePrivacy), consolidated texteur-lex.europa.eu
- ICO: Electronic mail marketing (guide to PECR)ico.org.uk
- M3AAWG Sender Best Common Practices, version 4.0 (August 2026)m3aawg.org
All 432 terms in the glossaryThe wiki: blocklists and bounce codes