This is the recommended setting if you do not have a cloud-based spam filter in front of GSuite. The setting may take up to an hour to propagate to all users, so wait at least an hour before testing.
- Log in to https://admin.google.com. You should see a screen as shown below. This is your Google Admin console.
- Go to Apps.
- Go to GSuite.
- Go to Gmail.
- Scroll to the bottom of the Gmail page and select Advanced Settings.
- On the left, select your domain.
- Scroll to the Email Whitelist setting in the Spam section. Or, in the search field, enter Email Whitelist
- Enter the following IP networks:
- IPv4: 220.127.116.11/22
- IPv6: 2a0b:6800::/29
- Scroll down to the bottom of the page, and click Save.
Note: It can take up to an hour for any changes to take effect. You can track changes in the Admin console audit log.