curl --request GET \
  --url https://www.getinboxzero.com/api/v1/stats/by-period \
  --header 'API-Key: <api-key>'

{
  "result": [
    {
      "startOfPeriod": "<string>",
      "All": 123,
      "Sent": 123,
      "Read": 123,
      "Unread": 123,
      "Unarchived": 123,
      "Archived": 123
    }
  ],
  "allCount": 123,
  "inboxCount": 123,
  "readCount": 123,
  "sentCount": 123
}