ChatMessage

{
    "_id": "64a1b2c3d4e5f6a7b8c9d0e1",
    "chatThreadId": "64a1b2c3d4e5f6a7b8c9d0e1",
    "from": "user@example.com",
    "to": "user@example.com",
    "subject": "string",
    "body": "string",
    "direction": "inbound",
    "createdAt": "2019-08-24T14:15:22.123Z"
}