As of October 2018, Proofpoint has said KnowBe4's IPs and hostnames are fully whitelisted. If you're still experiencing issues, follow the steps in the below article, or reach out to Proofpoint for specific assistance.
How to Whitelist in Proofpoint
If you're using Proofpoint's spam filtering, you can whitelist KnowBe4 to allow our simulated phishing test emails and training notifications through to your end users.
If your phishing security test emails are bouncing with the following error message, see the How to Prevent Proofpoint from Bouncing Emails section of this article.
- "Sender address rejected: Domain not found (in reply to RCPT TO command)"
Whitelisting in Proofpoint
When you're ready to whitelist in Proofpoint, follow the below instructions:
- From your Proofpoint admin center, navigate to Email Firewall, then Rules.
- Be sure to select the On radio button for Enable, under Rule Settings.
- Name your rule ID something such as "KnowBe4 Whitelisting by IP Address," and provide a description such as "KnowBe4 Phishing and Training emails."
- Under the Conditions section you will whitelist KnowBe4 by our IP addresses using the Add Condition button. For the most up-to-date list of our IP addresses, please see this article.
- Under Dispositions, change the Delivery Method to Deliver Now.
How to Prevent Proofpoint from Bouncing Emails
If some of your phishing security test (PST) emails are bouncing with an error message of
"Sender address rejected: Domain not found (in reply to RCPT TO command)",
follow the instructions below to resolve this issue.
- Navigate to your KnowBe4 Account Settings by clicking on your email address in the top-right corner and then click Account Settings.
- Scroll down to the Phishing section and ensure that the Disable return path header option is not enabled (see below).
- Be sure to save this change by clicking the Update Account Info button at the bottom of the page.
- To confirm this change will prevent Proofpoint from causing your PST emails to bounce, we recommend you test this change. You can do this by sending a test campaign to yourself or a limited number of users before sending it to a larger group.
What to Do If Your Emails are Going to Spam
If your emails are being sent to spam or are being quarantined, you'll need to add KnowBe4 to the Organizational Safe List in Proofpoint.
Follow the instructions below to add KnowBe4's hostnames or IP addresses to the Organizational Safe List:
- From your Proofpoint admin center, navigate to Email Protection > Spam Detection > Organizational Safe List.
- Add either our hostnames or IP addresses. For the most up-to-date list of our IP addresses and hostnames, please see this article.
Still need assistance? Submit a support ticket and we can help.