Your mail client may automatically place a warning banner on emails that come from a sender who is outside of your organization. When this banner displays, it may affect the way your user interacts with the phishing test and may cause inaccurate phishing test results. This guide will show you how to remove these warnings from KnowBe4 phishing emails.

How to Remove the Warning Banners in Your Organization

To remove external warning banners from emails that are received by your users, you will need to whitelist KnowBe4 in your mail client. If you’re using advanced delivery policies, navigate to the How to Remove the Warning Banner With HTML section of this article.

1. Navigate to your Exchange or Microsoft 365 account.
2. Log in to your mail server admin portal and click Admin.
3. On the left side of the page, navigate to Admin Centers > Exchange. You’ll be redirected to the Microsoft Exchange admin center.
4. On the left side of the page, navigate to Mail flow > Rules.
5. Select the check box next to the last KnowBe4 mail rule in your priority list. Then, click Edit.
6. Click More options.
7. Select the checkbox followed by the text Stop processing more rules.
8. Click Save.
9. Click on the mail rule used to add external warning banners in your organization. The name of this rule may vary depending on your organization’s mail rules.
10. Using the arrow icons beneath Rules, move the priority of your warning banner mail rule beneath KnowBe4’s whitelisting mail rules.

If you have a custom mail flow rule that adds an external warning message to emails received from outside of your organization, you can add an exception to that rule for KSAT emails.

1. Navigate to your Microsoft Exchange or Microsoft 365 account.
2. Log in to your mail server admin portal and click Admin.
3. On the left side of the page, navigate to Admin centers > Exchange. You’ll be redirected to the Microsoft Exchange admin center.
4. On the left side of the page, navigate to Mail flow > Rules.
5. Locate your mail flow rule that adds the warning message.
   1. Click on the rule > Edit rule settings > Conditions.
   2. Click the plus icon by Except if.
   3. Select The sender and IP address is in any of these ranges or exactly matches.
   4. Click the pencil icon. 
   5. Enter the KnowBe4 IP addresses. KnowBe4’s sending IP addresses can be found in our Whitelisting Guide.
   6. Save the rule.

If you have a custom mail flow rule that adds an external warning message to emails received from outside of your organization, you can add an exception to that rule for KSAT training notification emails.

1. Access your KSAT console Account Settings > Training.
2. Under Training Email Headers enable Add Custom Header > Configure the header name as desired. Make the header value a unique string.
3. Navigate to your Microsoft Exchange or Microsoft 365 account.
4. Log in to your mail server admin portal and click Admin.
5. On the left side of the page, navigate to Admin Centers > Exchange. You’ll be redirected to the Microsoft Exchange admin center.
6. On the left side of the page, navigate to Mail flow > Rules.
7. Locate your mail flow rule that adds the warning message.
   1. Click on the rule > Edit rule settings > Conditions.
   2. Click the plus icon by Except if.
   3. Select The messages headers… and matches these text patterns.
   4. Click the pencil icon.
   5. Enter the header names you created in KSAT.
8. Save the rule.

How to Remove the Warning Banner With HTML

You can remove the warning banners by adding CSS to the HTML’s header tag. By using this method, you can hide the warning message while maintaining the body of the email. However, users may still see the external warning banner when previewing the email in some mail clients. This implementation will also need to be used on every KnowBe4 phishing template, which may be time consuming.

For more information about how you can use HTML styling to hide banners in your own mail client, see WhyNotSecurity’s MS External Email Warning Bypass article.

Any mail rules beneath KnowBe4’s whitelisting rule in the mail rules hierarchy will no longer be processed and external warning banners will not be added to your emails. For further assistance with this bypass, please contact our support team and they will be happy to help.