Manually Controlling IP Exceptions in Microsoft 365 Mail Flow Rules

During onboarding, Email Security automatically creates several Mail Flow rules (see Automatic Mode Onboarding - Microsoft 365 Footprint). To prevent email delivery issues such as mail loops, the system automatically adds the Check Point IP addresses, along with all IP addresses from inbound connectors in the Microsoft 365 account at the time of onboarding, as exceptions in the Check Point Mail Flow rules.

In some cases, you may prefer to manage the list of IP exceptions in the Check Point Mail Flow rules manually.

Note:

Modifying IP exceptions in Check Point Mail Flow rules must be done carefully, as it may cause email delivery issues. This approach is not recommended. If you choose to modify IP exceptions manually, contact Check Point Support before making any changes.

  1. Create a new Threat Detection Policy for Incoming Emails (Prevent (Inline)) or open an existing one.
  2. Scroll down to the Advanced section.
  3. Select Configure excluded IPs manually in mail flow rule checkbox.

  4. Click Save and Apply.