curl --request GET \
  --url https://app.sendmux.ai/api/v1/mailbox/threads/{thread_id}/content \
  --header 'Authorization: Bearer <token>'

{
  "ok": true,
  "meta": {
    "request_id": "<string>",
    "thread_id": "<string>",
    "participants": [
      {
        "email": "agent@example.com",
        "name": "Support"
      }
    ],
    "states": {
      "thread_state": "<string>",
      "email_state": "<string>",
      "option_hash": "<string>"
    }
  },
  "data": [
    {
      "id": "<string>",
      "thread_id": "<string>",
      "subject": "<string>",
      "participants": {
        "from": {
          "email": "agent@example.com",
          "name": "Support"
        },
        "to": [
          {
            "email": "agent@example.com",
            "name": "Support"
          }
        ],
        "cc": [
          {
            "email": "agent@example.com",
            "name": "Support"
          }
        ],
        "bcc": [
          {
            "email": "agent@example.com",
            "name": "Support"
          }
        ],
        "reply_to": [
          {
            "email": "agent@example.com",
            "name": "Support"
          }
        ]
      },
      "dates": {
        "received_at": "<string>",
        "sent_at": "<string>"
      },
      "body": {
        "text": "<string>",
        "html": "<string>",
        "is_truncated": true,
        "truncated_at_chars": 123,
        "signature_stripped": true,
        "quotes_stripped": true,
        "extracted_links": [
          "<string>"
        ]
      },
      "headers": {
        "selected": {
          "message_id": [
            "<string>"
          ],
          "in_reply_to": "<string>",
          "references": [
            "<string>"
          ],
          "reply_to": [
            {
              "email": "agent@example.com",
              "name": "Support"
            }
          ]
        },
        "full": [
          {
            "name": "<string>",
            "value": "<string>"
          }
        ]
      },
      "attachments": [
        {
          "id": "<string>",
          "filename": "<string>",
          "content_type": "application/pdf",
          "size_bytes": 123,
          "disposition": "<string>",
          "content_id": "<string>",
          "download_url": "<string>"
        }
      ],
      "states": {
        "email_state": "<string>",
        "option_hash": "<string>"
      }
    }
  ],
  "pagination": {
    "has_more": true,
    "next_cursor": "<string>"
  }
}