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List-Unsubscribe & One-Click Checker
Gmail and Yahoo require one-click unsubscribe on bulk marketing mail. Paste the raw headers of one of your emails and see whether the List-Unsubscribe and List-Unsubscribe-Post headers are set up the way they expect - and what to change if not.
What this does - and doesn’t - tell you
What’s checked
- One List-Unsubscribe header, with its targets in angle brackets: an https URL and, optionally, a mailto: address.
- A List-Unsubscribe-Post header set to exactly
List-Unsubscribe=One-Click, as RFC 8058 requires. - That your DKIM signature covers both headers - the standard requires it, and Gmail checks it.
Worth knowing
- It reads headers only. It can’t see whether the link actually unsubscribes the person - test that yourself - or whether the visible link in the body is there.
- Gmail and Yahoo require one-click on bulk marketing mail (about 5,000+ a day) and expect unsubscribes honoured within two days. Cold outreach below that isn’t required to have it, but it lowers complaints, which is what protects your domain.
- The headers are added by the sending platform at send time, so check a message you actually sent, not the template. Check the rest of the Gmail and Yahoo rules with the Sender Requirements Checker.
Setting up one-click unsubscribe and signing the headers correctly depends on your sending platform. We configure it and verify it on a live message.
How we help: Consulting · Private infrastructure · Managed mailboxes · Monthly support