recipient_not_allowed

Recipient not allowed. Answered with 403.

What it means

Outbound mail goes to Allowed Recipients only. A recipient is on neither the Identity's list nor the Org's, and the send was refused at the Policy Point – the one gate both the REST send and an SMTP submission pass.

What to do

Have a human add the recipient with an Admin Key, or let it be granted automatically by mail that arrives from it and proves its origin. An agent never adds its own recipients.

The body

{
  "type": "https://tigby.eu/problems/recipient_not_allowed",
  "title": "Recipient not allowed",
  "status": 403,
  "detail": "…what was refused, naming this request's own values",
  "code": "recipient_not_allowed",
  "doc_url": "https://docs.tigby.eu/errors/recipient_not_allowed",
  "agent_hint": "…the next step, for software"
}

Branch on code. The detail names this request's own Handle, id or limit and is not part of the contract.