The Senders page will allow you to edit and add new Sender's email.
Adding a sender
To add new sender to your account you need to hover over you account name and click on Account, then, click on the Senders tab. From this page you will be able to click on + button and add the information.
A confirmation email will be sent to this email and will need to be verified before this email can be used to send campaigns.
Once a sender is added, it can also be delete or edited.