adapter_error

EmailAdapterError exposes:

• adapter
• optional HTTP status
• optional provider requestId
• optional acceptedCount and rejectedCount when the provider reports only aggregate recipient outcomes
• retryable
• delivery: "not_sent" | "unknown"
• standard cause

not_sent means fallback may proceed. unknown means delivery cannot be ruled out and fallback stops by default.

if (error instanceof EmailAdapterError && error.delivery === "unknown") {
  await reconcileProviderState(error.requestId);
}

A retryable flag does not override abort or unknown-delivery policy. It only participates in the configured retry decision for the current adapter.