For making default CC:
Go to file --> Info --> Rules and Alerts on window will come
Then on this window click on new rule button (top left)
Then select Apply Rule on message I sent and click on Next
Then select sent to people or public group and select people from Address Book on double click on name and click OK.
Then rule will come to bottom text area of windows then click Next
Given some name to this rule and click on finish to finish this activity.
Send one test mail to verify.
After that when you want to edit or delete rule You need to select rule name which you provided for this rule.