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Glossary

One-click unsubscribe

One-click unsubscribe is the standard, RFC 8058, that lets a mail app unsubscribe someone with a single automatic web request, so the recipient never sees a confirmation page or a login.

Updated · By Otman Ounana · How we research

Why it matters when you send from your own Gmail

It adds a second header, List-Unsubscribe-Post, which must contain the single pair List-Unsubscribe=One-Click.[1] Google requires it of senders above 5,000 messages a day to Gmail accounts for marketing and subscribed messages.[2] A person sending 50 a day is far below that, but the header is still worth having, because it turns an annoyed recipient into a clean opt-out instead of a spam report. Honest Intros adds it to every email, and the request suppresses the address for your account.

Example

The mail app sends an HTTPS POST to the link in the List-Unsubscribe header. The sender's server records the opt-out and answers. The recipient sees only that they were unsubscribed.

What to do

Test it once with a message to yourself: use the Unsubscribe link in Gmail, then confirm your own address was added to the list and that a later email to it does not go out.

Related terms

All terms are on the glossary.

Read next

  • RFC 8058 explainedWhat RFC 8058 one-click unsubscribe requires: the two headers, the HTTPS POST, DKIM, why it exists, and who now demands it (Gmail, Yahoo).
  • One-click under 5,000 a dayGoogle's one-click unsubscribe rule starts above 5,000 messages a day. What still applies below that, what the law asks for, and why a one-click link is worth adding anyway.
  • Send cold email from your own Gmail, safelyHow to send cold email from your own Gmail without hurting your reputation: daily limits, warm-up, working hours, unsubscribe and bounce brakes.
  • How fast to honour "remove me"The deadlines for honouring an unsubscribe or "remove me" reply after a cold email: UK, EU, US and Canada, quoted from the regulators and the laws, plus Gmail and Yahoo.

Sources

  1. IETF, RFC 8058: Signaling One-Click Functionality for List Email Headers. “The List-Unsubscribe-Post header MUST contain the single key/value pair "List-Unsubscribe=One-Click".” Read on 1 October 2026.
  2. Google, Email sender guidelines. “If you send more than 5,000 message per day, your marketing and subscribed messages must support one-click unsubscribe.” Read on 1 October 2026.