1. Once logged in to your account, go to the "Marketing" tab and choose "Sender Settings".
This is the marketing button on your main navigation bar.
2. Once in your sender settings add in your sender name (Business name) and reply to an email (Business email).
3. Hit save and you'll have a new sender to choose from when sending out campaigns! You can have several different senders that you can alternate between when needed, such as when you have other sites.