Catch-all address routing
You use catch-all addresses to receive messages that are accidentally addressed to an incorrect email address for a domain.
Designate a catch-all address only when you really need it. Spammers often try to guess email addresses in your domain. When they guess incorrectly, the spam is delivered to the catch-all address. The volume of incoming messages can exceed the Gmail receiving limits, resulting in the account becoming locked. Or, it might lead to legitimate messages being deferred, delayed, or bounced.
You set up catch-all routing using the Routing setting. If you've set up a catch-all address for domain-level routing using the Email routing setting, you must convert the configuration.
You now use the Routing setting to configure catch-all addresses and routing for your domain and organizations. Previously, you used the Email routing setting and the Route to catch-all address control to set up a catch-all address for domain-level routing.
The Email routing setting is no longer supported. If you configured catch-all routing using this setting, you need to delete or convert the configuration. For details, see Domain-level routing.
This feature is only available with the legacy free edition of Google Apps.
From the dashboard, click Apps.
Click G Suite > Gmail > User settings.
In the Catch-all address section, select the Forward the mail to: option.
Enter the username for the catch-all address. The username must be a valid account in your domain. Don’t include the domain name, @your-domain. It’s automatically added to the address.
At the bottom, click Save.
To bounce messages addressed to nonexistent recipients: