Sending guide

List-Unsubscribe header and one-click unsubscribe

What the List-Unsubscribe headers are, what Gmail and Yahoo require, and how to add one-click unsubscribe.

What the List-Unsubscribe header is

List-Unsubscribe is a hidden header in an email that tells the inbox how to unsubscribe the reader. Gmail, Yahoo and Outlook use it to show their own “Unsubscribe” button at the top of the email, so people leave your list instead of marking you as spam.

One-click unsubscribe

Since 2024, Gmail and Yahoo require bulk senders (around 5,000 or more emails a day) to support one-click unsubscribe for marketing email, and to act on requests within two days. One-click means the inbox can unsubscribe the reader with a single request, without them visiting a page or logging in.

The headers

List-Unsubscribe: <https://yourdomain.com/unsubscribe/abc123>, <mailto:unsubscribe@yourdomain.com?subject=unsubscribe>

List-Unsubscribe-Post: List-Unsubscribe=One-Click

The second header tells the inbox it can send a POST request to the https address to unsubscribe the reader instantly. The address must work without a login and must actually remove them.

How to add it

Newsletter and marketing platforms such as Mailchimp and Brevo add both headers for you on campaigns.
Cold email tools usually offer an unsubscribe link and, in some, a header option. Check your tool’s settings and turn it on.
Your own system needs to add both headers and handle the POST request.

Even below the bulk sender threshold, an easy way out lowers spam complaints, and complaints are one of the main reasons emails go to spam.

Check the rest of the rules

One-click unsubscribe sits alongside SPF, DKIM and DMARC in the bulk sender rules.