I think you got it wrong what i meant (?)
Imagine i register on a website with my username ( DacoTaco ) and email ( someEmail@domain.com ). When i want to reset my password and click the “forgot password” link, it would ask my username, not my email address (something i know) and send me an email ( to someEmail@domain.com ) without reporting what email it sent it too. That way it could be considered a separate identity factor i think (access to the mailbox, something you have ).
Websites generally dont work this way, i know. But thats how id implement it :')