Hi @Mark_H, currently this is not possible in Duo. In the field for Notify a specific email address, you can only enter a single email address.
Our recommendation is typically to create an email distribution group that includes all the stakeholders you want to notify and add that email address in the Lockout and Fraud settings of the Duo Admin Panel. However, you mentioned this would not fit well for your scenario. Out of curiosity, can you provide more context as to why the available options aren’t sufficient for you?
It’s also worth noting that we have a feature request for this functionality. Please talk to Duo Support or your Customer Success Manager or Account Executive (if applicable) about getting added to the request.