For Catch All accounts follow the link.
To create a catch-all address for delivering messages addressed to non-existent recipients:
- Sign in to the Google Admin console.
- Click Google Apps > Gmail > User settings. Where is it?
- (Free edition) In the Catch-all address section, select the Forward the mail to: radio button. (Other editions) In theEmail routing section, select the Route to catch-all address: radio button.
- Enter the user name to which mail addressed to unknown users will be forwarded. The user name must be a valid account in your domain. Do not include the domain name; Google Apps automatically adds @your-domain to the address.
- Click Save changes.
To bounce messages addressed to non-existent recipients: