This is possible, the keyword is "Event Handlers". You will have to write an Event Handler that reacts to the Process Cube action, and sends out the email. There are examples scattered through the documentation and forums.
Consider that Handlers are a fairly advanced topic; because they effectively run after almost every action, if you do them badly you might tank performance for a lot of activities. You're jumping in right at the deep end, and might want to discuss it with someone a bit more senior in the space. Good luck!
