Decodes the tamper-proof, server-encrypted UnsubscribeToken from a campaign-email unsubscribe link and returns the masked recipient address plus whether they are already on the suppression list. Render-only — no state change. A generic the endpoint returns 404 for any invalid/expired token so the response never reveals whether a specific address or token is valid.

Path params

Auth

• Public — no bearer token (unauthenticated campaign group; item marked noauth). Reached from the unsubscribe link in customizable emails.

Rate limit

• 30 requests/min per IP (public).

Behaviour

• 200 { status: "success", data: { email_masked, already_unsubscribed } }. email_masked shows only the first local-part character (e.g. j***@example.com); already_unsubscribed is true when the address is on the blacklists suppression list.
• 404 (notFoundResponse) "Invalid or expired unsubscribe link." for any bad/expired token.