To achieve this, you can use a combination of two rules in Outlook:
- Create a rule to automatically Cc the depository email with every email sent, without any conditions.
- Create a second rule with the condition "specific words in the subject" and add the word "confidential" to the list of specific words.
- In the "actions" section of the second rule, select "stop processing more rules" option.
This way, when an email is sent with the word "confidential" in the subject, the second rule will be triggered and the email will not be Cc'd to the depository email as the rule processing will be stopped.
If the word "confidential" is not in the subject, the first rule will be triggered and the email will be Cc'd to the depository email as usual.
Make sure the rules are in the correct order, with the second rule placed above the first rule in the list of rules, so that it is processed first.