# route_error (/docs/reference/errors/route-error)



`EmailRouteError` has code `route_error` and an ordered `failures: readonly EmailAdapterError[]` array.

The array contains every terminal adapter failure reached by the route. Unknown delivery may stop the route before later configured adapters are attempted.

```ts title="src/send.ts"
if (error instanceof EmailRouteError) {
  for (const failure of error.failures) {
    console.error(failure.adapter, failure.delivery, failure.status);
  }
}
```

The error cause is the final failure in the array. Preserve ordering in diagnostics because it explains primary, retry, and fallback decisions.