# SY40012: Validation failed for Recipient: mailable_type can't be blank

Source: https://developer.synup.com/errors/sy40012

Documented under Notifications.

```json
{
  "data": null,
  "errors": [
    {
      "message": "Validation failed for Recipient: mailable_type can't be blank",
      "context": {},
      "code": "SY40012"
    }
  ]
}
```