To edit your CAN-SPAM message, go to the templates for your campaign that you wish to edit the CAN-SPAM message for. (If you don’t currently see a CAN-SPAM message in your template, check the box underneath the body of your email. This will open a text box with your CAN-SPAM message that you can edit.)
The information in this message (like your address) is pulled directly from your project settings. You can edit this information by going to Settings > Project Settings. You will see a section titled 'Physical Address to be included as a part of CAN-SPAM footer' where you will be able to edit your information.