The script automatically updates the router to the latest firmware.
When script finds new update it sends an email notification that upgrade process has started, system backup and config file are in the attachment. After firmware and routerboard got updated, it sends the second email which tells that upgrade process finished.
Set your email server parameters. If you don't have one, i recommend to use [smtp2go.com](https://smtp2go.com "smtp2go.com") service, it allows sending a thousand emails per month for free.