It will update the ccEmail Address to invalid for all Email ALerts for any SObject in your Sandbox
A simple way to change the ccEmail address of Email Alert used in Workflow Rules is to ensure your email data is protected and no test email is sent to the customers. You can use this Google extension both in Lightning and Classic Experience in Salesforce.
In Classic, you just need to open the WorkflowRules URL page. In which you will see the Email Change Button. Click on it and your ccEmail address will be changed successfully.
In Lightning, you just need to open the WorkflowRules URL page. You will see Authorize button click on it and after some time you will see the Email Change Button. Click on it and your ccEmail address will be changed successfully.