When you create a staging site, you can decide to disable email sending to prevent the staging site from sending mails. This can be very helpful because you don’t want to allow the staging site to send out emails to your customers like newsletters, license reminders, or any other shop transaction-related mail.
Sometimes you want to change this, for instance, if you want to test a certain feature’s mail capabilities.
If you want to allow sending emails from your staging site, log in to your staging site and go to WP STAGING > Settings > Mail Settings
From there, you can activate the checkbox and allow sending mails from the staging site.