How to add Domain Forwarding email in Builder:

1) Under "Site" menu on left side of builder

2) Select "More"

3) Click on "Domains & Emails"

4) Double click on the domain you wish to add Forwarding emails to

5) Click the "+" Icon at the bottom left corner of builder

6) Enter text to create an email attached to the domain added

7) Once created you can add the email you wish it be forwarded to

Make sure to publish and test, this change may take a couple hours to propagate.