This article contains recommendations and best practices to use if your mail is hosted on Google Workplace.
Create an Inbound Gateway
When you create an inbound gateway, you are telling Google that your mail is processed by MX Guardian before reaching the Google servers.
To create an inbound gateway:
- Sign in to the Google Admin console.
- From the dashboard, go to Apps > Google Workspace > Gmail.
- Scroll down to Spam, phishing, and malware
- Click the pencil icon to the right of Inbound gateway.
- Select the checkbox to enable the feature.
- Under Gateway IPs, add the MXGuardian IP addresses which can be found at https://mxguardian.net/ips. You need to add each address one at a time. The steps are:
- Click Add
- Type (or copy & paste) the first IP address
- Click Save
- Repeat for each of the IP addresses listed
Note: Please make sure to add both the IPv4 and IPv6 addresses
- For the highest level of security, select these three checkboxes:
- Automatically detect external IP
- Reject all mail not from gateway IPs
- Require TLS for connections from the email gateways listed above
- Click Save at the bottom of the Inbound Gateway section. The changes should take effect in a few minutes.
More information can be found at: https://support.google.com/a/answer/60730?hl=en