If you are not familiar with this feature, G Suite allows one user (or group) to be the default receiver of all email that goes to an email address at your domain that is not connecting to a user. For example, a typo of a name:

rob.beddis@domain.com instead of rob.bettis@domain.com

or the wrong formatting:

rbettis@domain.com instead of rob.bettis@domain.com

Because it took me entirely too long to figure out how to set a catchall, I wanted to create a quick and current tutorial on how to accomplish what used to be a basic feature.

Note: in my limited research, existing Google Apps / G Suite accounts retained the older (much more simple setting (Apps > G Suite > Gmail > Advanced > Catchall Address). But if your G Suite account was created in late 2017 or later, then the following directions should work for you.

1. Login to your admin panel (https://admin.google.com/AdminHome)

2. Navigate to Apps > G Suite > Gmail (https://admin.google.com/AdminHome?hl=en#AppDetails:service=email)

3. Choose 'Default routing'.

4. Choose 'Add Setting'

5. Configure The New Setting

You will make 2 changes to the default settings:

1. Change the selection to 'All Recipients'
2. Under 'Also deliver to', choose 'Add more recipients'.
3. 
   

6. Click Save

7. Disable Default Setting

With the new setting saved, you now have two settings in your 'Default routing' panel.

1. The previous setting will send an 'undeliverable' email to any users who send email to a non-existent user at your domain.
2. The new setting that we just created will forward the message to the established catchall address.

That might be your preferred behavior. If so, you are all done. However, I preferred to deliver the email to the catchall without sending the 'undeliverable' email to the sender. If you are like me, you need to complete one more step.

8. Disable The Old Setting

Select Setting #1 and choose 'Disable'.

Finished

That should do it. All told, you should have something that looks like...