To be in compliance with the CAN-SPAM act, the footer for an email has to be updated with your company details before sending any campaign. 

Navigate to Settings -> Email Campaign Settings -> Footer Details.

Provide the company details on the mandatory fields and click 'update'. This will automatically get updated on the footer of the emails which you create.

Primary and Additional footer addresses:

More than one Footer address can be configured using Freshmarketer. Any one of the addresses can be set as Primary at a time. 

Click on "Add New Address" to include a new footer address.

There are no restrictions on the number of the addresses that can be added. The remaining addresses added will be shown as additional ones having the option to set as primary. Please refer to the below screenshot.

The primary address set will be populated on your Email templates by default.

Including company details from the editor:

In the campaign Design tab, the company details can be added to the footer block by using Merge Tags option. If they are not included manually, the default footer settings will be included as shown below. This default text can also be customised using the template editor.

You will not be able to send the campaign if the footer settings are not set. A warning will be shown on the Review tab under the design issues. After updating your company details, you can edit the same before sending a campaign using the below Edit option.

Note: This setting is global for all the campaigns you create and this can be edited at any time.