Each Folio account can only have one email account associated with it. It's a 1-to-1 relationship, which means it will only be able to see the emails related to the email account it was connected to. If you changed your email address or domain, you will likely need to start a new Folio account. Read more about that here.
Each account has separate service providers, resources, and timeline templates. Currently, there is no option to share those among accounts.
You can share Timelines among multiple email accounts if you want to control the same Timeline from different accounts. Learn more about that here.