curl --request GET \
  --url https://app.sendmux.ai/api/v1/mailbox/messages/search-snippets \
  --header 'Authorization: Bearer <token>'

{
  "ok": true,
  "meta": {
    "request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
  },
  "data": {
    "snippets": [
      {
        "message_id": "<string>",
        "subject": "<string>",
        "preview": "<string>"
      }
    ],
    "not_found": [
      "<string>"
    ],
    "sync_state": "<string>"
  }
}