To add a footer to all outbound emails, hover over this section and click CONFIGURE:

Once the form appears, add a short description of this footer and write the footer you wish to use for outbound messages. If you also wish to add the footer for messages sent internally, simply enable the checkbox at the bottom in the Options section. Once you have everything ready, click ADD SETTING.

In the Append footer form, start by writing a short description for this footer and then write the footer as you wish in the text box:

Optionally, you can choose to also append this footer to messages sent within the team: