Errors

recipient_invalid

400 – Not an address. One of the addresses in to, cc or bcc is not an address a message can be sent to.

Not an address. Answered with 400.

What it means

One of the addresses in to, cc or bcc is not an address a message can be sent to.

What to do

Send addresses as plain name@example.com; the detail names the one that was refused and the field it was in.

The body

{
  "type": "https://tigby.eu/problems/recipient_invalid",
  "title": "Not an address",
  "status": 400,
  "detail": "…what was refused, naming this request's own values",
  "code": "recipient_invalid",
  "doc_url": "https://docs.tigby.eu/errors/recipient_invalid",
  "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.