Yes, a field could be added to address as well, but that's not a very common practice for systems like this. If you'd like to get this quickly, there are custom modules out that will allow you to make and store custom fields in the system. The datakick module is one of them that I can vouch for https://store.getdatakick.com/en/modules/datakick-data-export-and-import.
Your challenge will be using that stored email in your automated business logic. If that is something not needed, then a solution like a module to help you will work well.