RFC 8058 is the internet standard that defines one-click unsubscribe for email. It lets a mail app such as Gmail or Yahoo Mail unsubscribe someone directly, with a single action inside the app, without opening a web page or sending an email. It builds on the older List-Unsubscribe header by adding a second header that tells the app the link can be called automatically.
Technically, the email carries two headers. List-Unsubscribe contains an HTTPS link that is unique to the recipient. List-Unsubscribe-Post contains the exact value “List-Unsubscribe=One-Click”. When the user unsubscribes in the app, the mail provider sends an HTTP POST request to that link, and the sender’s system must unsubscribe the recipient without asking for confirmation or a login. The standard also requires the email to have a valid DKIM signature covering both headers.
Since 2024, Gmail and Yahoo have required bulk senders to support one-click unsubscribe for marketing and subscribed messages, and to honour the request within two days. Transactional messages, such as receipts and password resets, are not expected to include it. A visible unsubscribe link in the body is still needed as well.
The POST approach exists for a practical reason. Security scanners and link-preview systems often visit every link in an email with a GET request. If simply visiting an unsubscribe link removed people, scanners would unsubscribe them by accident. Requiring a POST with a specific body means only a deliberate action through the mail app triggers the unsubscribe.
A Mumbai news site sends a daily briefing to 80,000 readers. A reader taps “Unsubscribe” beside the sender name in Gmail. Gmail sends a POST request to the link in the header, the site’s platform unsubscribes her within seconds, and she receives no further briefings.
MailNesto adds both List-Unsubscribe and List-Unsubscribe-Post headers to campaigns, processes one-click requests from mail apps immediately and records them as “One-click unsubscribe (mail app)” in the contact’s consent history.