Manually Controlling IP Exceptions in Microsoft 365 Mail Flow Rules

During onboarding, Avanan 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 Avanan IP addresses, along with all IP addresses from inbound connectors in the Microsoft 365 account at the time of onboarding, as exceptions in the Avanan Mail Flow rules.

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

Note:

Modifying IP exceptions in Avanan 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 Avanan 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.

When are my changes overridden

Changes made to IP addresses in Avanan Mail Flow rule exceptions are not overridden immediately, regardless of whether the checkbox is selected.

However, changes may be overridden in the following situations:

  • Inline Protection for Internal Emails

    When the Protect (Inline) Internal Traffic option is enabled or disabled in a Prevent (Inline) policy, Avanan automatically updates the Avanan - Protect Internal Mail Flow rule.

    • If Configure excluded IPs manually in mail flow rule is not selected, your changes to this rule are overridden.

    • If Configure excluded IPs manually in mail flow rule is selected, your changes to this rule are not overridden.

  • Occasional Support Intervention

    In some cases, Avanan Support may need to recreate or update Mail Flow rules while handling a support ticket.

    • If Configure excluded IPs manually in mail flow rule is not selected, the rules are recreated, and your changes are overridden.

    • If Configure excluded IPs manually in mail flow rule is selected, the rules are updated, but your changes are not overridden.