Unsubscribe
The way a recipient stops future mail from a sender: a link in the message, the List-Unsubscribe header or a reply. Laws and providers set how fast it must work.
What it means
Law and provider rules converge here. CAN-SPAM requires a clear way to opt out of commercial mail, working for at least 30 days after sending, honoured within 10 business days, with no fee and nothing asked beyond an email address and preferences. CASL requires an unsubscribe mechanism in every commercial electronic message, given effect within 10 business days. Google requires bulk senders to support one-click unsubscribe (RFC 8058) for marketing mail and show a visible link, and recommends honouring requests within 48 hours; Yahoo requires 2 days.
M3AAWG adds that unsubscribing must not require logging in, that an unsubscribe should default to all mail when no preference center is offered, and that replies to the From address should be accepted as requests.
The unsubscribed address goes straight to the suppression list.
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
- Google: Email sender guidelinessupport.google.com
- Google: Email sender guidelines FAQsupport.google.com
- Yahoo Sender Hub: Sender requirements and recommendationssenders.yahooinc.com
- RFC 8058: Signaling one-click functionality for list email headersrfc-editor.org
- M3AAWG Sender Best Common Practices, version 4.0 (August 2026)m3aawg.org
All 432 terms in the glossaryThe wiki: blocklists and bounce codes