When Key Name is not specified the output is in JSON format. By specifying the Key Name values, you can selectively extract contents within JSON
Key Names are
① message_id
② account
③ body
④ send_time
⑤ update_time
Target
Last 100 messages: outputs 100 latest messages
Since last time: outputs only the new messages from the last access
Output/Return Value
JSON output for String, CSV, and File
When multiple messages are included line change is added at the end of one message ID. Likewise, multiple lines are returned when Key Names are specified.