curl --request GET \
  --url https://api.lettermint.co/v1/messages/{messageId} \
  --header 'Authorization: Bearer <token>'

{
  "id": "<string>",
  "type": "inbound",
  "status": "pending",
  "status_changed_at": "2023-11-07T05:31:56Z",
  "tag": "<string>",
  "from_email": "<string>",
  "from_name": "<string>",
  "reply_to": [
    "<string>"
  ],
  "subject": "<string>",
  "to": [
    {
      "email": "<string>",
      "name": "<string>"
    }
  ],
  "cc": [
    {
      "email": "<string>",
      "name": "<string>"
    }
  ],
  "bcc": [
    {
      "email": "<string>",
      "name": "<string>"
    }
  ],
  "attachments": [
    {
      "size": 123,
      "filename": "<string>",
      "content_id": "<string>",
      "content_type": "<string>"
    }
  ],
  "metadata": {},
  "route_id": "<string>",
  "created_at": "2023-11-07T05:31:56Z",
  "spam_score": 123,
  "spam_symbols": [
    {
      "name": "<string>",
      "score": 123,
      "options": [],
      "description": "<string>"
    }
  ]
}