Every email that goes out of site will be copied to the email addresses set in CC and BCC fields. This can work as log for the admin to check whether any particular email is received by the user or not.
Testing Instructions
* Login into Administrator,
* Go to Global configuration,
* Go to Mail Settings,
* Configure mail settings with newly added **Add CC** and **Add BCC** fields,
* Save the settings,
* Try sendingTest Email.
Expected result
Any email sent from the site should also be received by the emails set in Add CC and Add BCC fields.
Please see that this feature is already in #22126. If that PR is merged, that would make this one obsolete.