Email a recovery link to each verified external owner of the inbox address. Returns HTTP 202 with the same body before the lookup and the email when the limit is checked. 5 per hour per IP and 3 per day per address, then HTTP 429 rate_limited. If the limit cannot be checked, the response is HTTP 503 rate_limit_unavailable with Retry-After, retry_after_seconds, and resets_at. An address at cooperemail.com or any subdomain, an inbox on any account, and any domain row are skipped. The key is not emailed.