From time to time you backup or clone a site and restore it to a temporary domain for testing or troubleshooting. This guide talks about completely disabling automations and emails that might cause problems.
There's two plugins that would really well to disable emails and log them.
wp plugin install --activate disable-emails log-emails
wp plugin instsall --activate https://github.com/Prospress/action-scheduler-disable-default-runner/archive/master.zip