I'd like Gemini to notify non-Gemini users when an event occurs on an issue (ie. when issue is closed).

Issues originates from various sources - often from users. When I add an issue that originates from a non-Gemini user to Gemini, I'd like also to be able to add one or more email-adresses for notification purposes and add one or more events to such notifications. This way I wouldn't have to worry about sending the user an email when the desired issue event occurs.