Deactivating the Microsoft 365 Spam Filter for the IP Address Range of Hornetsecurity

You can disable the Microsoft 365 spam filter to have incoming emails to your domains filtered by our services only.

If you want your incoming emails to be filtered by our services, you need to disable the Microsoft 365 spam filter. Otherwise, the Microsoft 365 spam filter would classify incoming emails to your domains as spam. Our services filter your incoming emails for spam.


Email authentication via SPF is not automatically enabled. Setting up SPF checks is not mandatory, but recommended. For setup information, see About Email Authentication.

  1. Log in to with your administrative credentials.
  2. Click on Admin.
    Figure 1: Admin button
  3. Under Admin Centers, select the item Security.

    If the Admin Center is not displayed in your default view, extend the menu with Show all.

  4. On the left side, open the Threat management menu and click on Policy.
  5. On the menu point Policies, click on Anti-spam.
    Figure 2: Create anti-spam policy
    The anti-spam settings open.
  6. Click on the arrow before Connection filter policy to extend the settings.
  7. Click on .
    Figure 3: Edit connection filter policy
    The menu Connection filter policy opens.
  8. Under Connection filtering, click on Edit after IP Allow list .
  9. Enter the following IP addresses one after the other into the input field and confirm the entry with +:,,,,,,,,,,,,,,,,,,,,,

    Figure 4: Add IP addresses to the list of allowed IP addresses
  10. Finally, click on Save to save the settings.

The spam filter of Microsoft 365 is deactivated for emails from our IP address ranges.