In order to comply with CSPAM (regulations for the sending of commercial emails) we automatically add your mailing address and an unsubscribe link to the bottom of your emails.
If you want to see what your mailing address looks like before sending an email use the Preview button on the Editor tab to take a look.
You can change this mailing address through the Account Settings option accessed from the Edit tab of the application. Once you have made changes click the Save Address button.
To learn more about how Unsubscribes work click here.