Whitelisting an IP Address in Microsoft 365 to Bypass Spam Filtering: A Step-by-Step Guide

As a business, you may occasionally need to ensure that important emails from specific IP addresses don't get caught in Microsoft 365's spam filter. This is called "whitelisting" an IP address. In this guide, we'll walk you through the process of creating a mail flow rule to whitelist an IP address, allowing emails from that address to bypass spam filtering in Microsoft 365.

Step 1: Access the Exchange admin center's transport rules page

Visit the Exchange admin center's transport rules page and sign in with your admin credentials: https://admin.exchange.microsoft.com/#/transportrules

Step 2: Edit the 'Bypass spam filtering' rule

Once you're logged in, locate the rule called "Bypass spam filtering" in the list of rules. Click on the pencil icon or the rule itself to edit it.

Step 3: Enable the rule

Ensure that the "Bypass spam filtering" rule is enabled by checking for a checkmark or toggle switch. If it's not enabled, click on the checkmark or toggle switch to enable it.

Step 4: Set the condition to whitelist an IP address

In the "Apply this rule if..." section, click the drop-down menu and select "The sender's IP address is in any of these ranges or exactly matches." A new window will appear, allowing you to input the IP address or IP address range you want to whitelist.

Step 5: Add the IP address or IP address range

Click the "+" (plus) button in the new window and enter the IP address or IP address range you wish to whitelist. Once you've added the necessary information, click "OK."

Step 6: Modify the message properties

Under the "Do the following..." section, click the drop-down menu and choose "Modify the message properties." From the sub-menu, select "Set the spam confidence level (SCL) to 'Bypass spam filtering.'"

Step 7: Stop processing more rules (optional)

Consider enabling the "Stop processing more rules" option. This ensures that no other mail flow rules will be applied to messages from the whitelisted IP address.

Step 8: Enforce the rule

In the "Choose a mode for this rule" section, make sure "Enforce" is selected.

Step 9: Save the changes

Finally, click "Save" to apply the changes to the rule. It may take a few minutes for the rule to take effect.

Conclusion

By following these steps, you've successfully created a mail flow rule to whitelist an IP address in Microsoft 365. Emails originating from the whitelisted IP address should now bypass spam filtering, ensuring that important messages from that address reach their intended recipients.