How do recipients unsubscribe?

One-click List-Unsubscribe suppresses that address on the sending tenant.

On bulk clusters, PostShiba adds a one-click unsubscribe header to each message. When a recipient uses it, we suppress their address for the tenant that sent the message, so later sends to them from that tenant are refused.

When we add the header

We add List-Unsubscribe and List-Unsubscribe-Post when all of these are true:

  • The message is sent on a bulk cluster. Transactional clusters never get it.
  • The message has exactly one recipient.
  • The message does not already have its own List-Unsubscribe or List-Unsubscribe-Post header.

If you set your own header, we leave both alone and your unsubscribe handling applies instead.

What the recipient sees

Many mail apps show an Unsubscribe button next to the sender when this header is present. The link goes to https://www.postshiba.com/unsubscribe/{token}.

  • Clicking the button in the mail app sends a one-click request. We suppress the address right away.
  • Opening the link in a browser shows a confirmation page first. Nothing changes until the recipient confirms.

Add a link to the message body

To also put an unsubscribe link at the bottom of the message, send the header X-Include-Unsubscribe: true. We remove that header before delivery. It only has an effect on messages that get the one-click header.

What you see

  • An unsubscribe event on the cluster and on your webhook, if the endpoint subscribes to it. See Event types.
  • A suppression with the reason Unsubscribe on the tenant that sent the message.
  • The next send from the same tenant skips that address with suppressed. See Errors.

Next steps