By default, Gmail lets users automatically forward incoming mail to another address. As an administrator, you can disable this option to prevent users from setting up automatic forwarding.
When you disable the option in the Control Panel, users won’t see the forwarding option in their Gmail settings.
Release track:
Rapid & Scheduled
Editions included:
Google Apps for Business and Education
Languages included:
All languages supported
For more information:
https://support.google.com/a/