Free tool
List-Unsubscribe header generator
Build the List-Unsubscribe and List-Unsubscribe-Post headers for one-click unsubscribe, or paste the ones you send to validate them. It runs in your browser. Nothing you type is sent anywhere.
List-Unsubscribe header generator
Build the headers
Unique to the recipient, and it must accept a POST with no login and no confirmation page.
Validate the ones you send
The three parts
What makes unsubscribe one-click
An https target
Inside angle brackets in List-Unsubscribe. A mailto target can sit beside it as a fallback, but cannot replace it.
The exact Post value
List-Unsubscribe-Post: List-Unsubscribe=One-Click, written exactly like that. It is what tells a client it may POST without asking.
A DKIM signature
It must cover both headers. Without it, a valid-looking pair of headers still fails the standard.
To check everything else a bulk sender needs, use the bulk sender checker. How we handle topics and opt-outs is in the topics docs.
FAQ
Questions about List-Unsubscribe
What is one-click unsubscribe?
RFC 8058 lets a mail client show an Unsubscribe button that works immediately. The message carries an https URL in List-Unsubscribe and List-Unsubscribe-Post: List-Unsubscribe=One-Click. When someone presses the button, the mailbox provider POSTs to the URL, with no page to load and nothing to confirm.
What must the unsubscribe URL do?
Accept a POST, identify the recipient from the URL alone, and unsubscribe them, with no login, redirect or confirmation step. Put a unique token in the URL, because the POST body carries only List-Unsubscribe=One-Click and no address.
Why not unsubscribe on a GET?
Security gateways and link scanners fetch URLs in mail automatically, so an unsubscribe on GET removes people who never asked. That is why RFC 8058 uses POST. If the same URL also opens in a browser, make the GET show a page with a button.
Does the DKIM signature have to cover these headers?
Yes. RFC 8058 requires a valid DKIM signature covering both List-Unsubscribe and List-Unsubscribe-Post, so a receiver can trust that the sender wrote them. Add both to the signed headers list in your DKIM configuration.
Do I still need an unsubscribe link in the message?
Yes. Gmail asks for a clearly visible unsubscribe link in the body as well as the header, and the header button does not appear in every mail client.
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Next step
One-click unsubscribe that also stops the sequence
SendRaven adds and signs these headers on marketing mail, handles the POST, and cancels the person's scheduled sends along with suppressing the address.