DIAGNOSTIC PLAYBOOK
One-click unsubscribe header is missing
An ordinary unsubscribe link and RFC 8058 one-click headers are different mechanisms. A message intended to support one-click needs the appropriate List-Unsubscribe and List-Unsubscribe-Post fields and a working endpoint.
HealthCheck Email editorial team · · Examples are illustrative
How to investigate
- Inspect a final received campaign message rather than a draft or template preview.
- Check the HTTPS unsubscribe target and the required POST signal in the headers.
- Verify the sending platform's one-click configuration and test with a controlled subscription.
What this looks like
ILLUSTRATIVE EXAMPLE
The email contains a footer link to a preference page but no one-click POST header. A visible link alone does not implement the one-click mechanism.
A mistake to avoid
Do not test by unsubscribing a real customer. Use a designated test subscriber and verify the resulting list state.
Keep the result in context
Inspect the original raw message rather than a forwarded screenshot. Headers can contain private addresses, message identifiers and routing information, so redact a separate copy before sharing. Give the most weight to results added by your own trusted receiving infrastructure.
Take the next step
Use the related check to gather evidence, then compare it with the affected message or service. Keep the result and time with your notes so a later change can be distinguished from the original problem.
Sources and further reading
The protocol references below explain the underlying behavior. Your sending or DNS provider supplies the account-specific settings for its service.