For many years, email marketers have either known or suspected that some of the opens and clicks recorded for their campaigns are not all being created by their subscribers. That instinct makes a lot of sense, as we know that email must be handled by software, firewalls, and filters whenever they are delivered.
For example, products like Barracuda’s Multilevel intent analysis have been around for over ten years now. Those filters have become increasingly sophisticated in how they examine email messages, follow the URLs and analyze links they contain for Calls To Action for your subscribers.
The phrase "Robot Clicks" has become a catchall term used to try and describe this automated behavior. A more accurate, and better description is Nonhuman Interactions or NHIs – we’ll use that term here.
Measuring the impact
The global industry association, Messaging, Malware and Mobile Anti-Abuse Working Group (M3AAWG) has conducted research on Nonhuman Interactions, how they function, where their use is seen, and what impact can be measured. They looked especially at whether the automated NHIs could be reliably identified and then filtered out leaving just the human clicks, that are seen as more genuine indicators of subscriber engagement.
B2C
M3AAWG’s research points to less than 10% impact by NHIs when sending to large Mailbox Providers such as gmail.com yahoo.com, outlook.com etc.
B2B
Businesses, various quasi-NGOs and non-profits, as well as academic institutions like universities and colleges, that value greater and more finely tuned control over their inbound email flows will make more use of enterprise level anti-spam software. They will also tend to err on the side of caution and apply stricter tests to the email they receive. Lower subscriber engagement correlated with increased scans and NHIs.
M3AAWG themselves concluded, “It is hard to quantify a summary effect, as most filter agents and ISPs work to mask detection. This is necessary to ensure filters are not circumvented, which would ultimately negate their effectiveness…”
In June 2023, many Office365-hosted subscriber mailboxes were generating clicks on almost every URL in the messages sent. This increased the count of Click Events by orders of magnitude, and although it has been seen to affect a very small proportion of senders, that creates much uncertainty as all the Click events are genuine, but clearly many are NHIs.
What Click has been doing about NHI
In June 2023 Click identified an increase in Total Clicks being recorded when emailing Office 365 hosted accounts. We opened an investigation and alongside our technology partner Microsoft found the increase was attributed to Non-Human Interactions (NHI), sometimes known as "Robot Clicks" as a catchall term used to describe clicks made by an automated program.
Microsoft has reported that the sudden and very large increase in NHI/robot-clicks, was due to changes that Microsoft have made to how their Safe Links feature in the Microsoft Defender for Office 365 product was scanning URLs.
As Microsoft is not the only provider of link scanning platforms and programs that generate NHIs, we continue to recommend the findings of the Messaging, Malware and Mobile Anti-Abuse Working Group - M3AAWG (https://www.m3aawg.org/blog/exploring-the-growing-impact-of-nonhuman-interactions-nhi-on-email-send-metrics) to help prevent even triggering those bot clicks in the first place.
Click has also identified ways to track and filter out various behaviors of NHI bot activity and have been improving these features since then.
Click NHI filter
April 2026 update - The NHI filter removes MPP and non-human interactions identified by Click algorithms. Using machine learning and behavioral modeling, it ensures real-time accuracy for active campaign metrics, reducing the number of NHIs that may impact your statistics.
As a result, you may see a reduced open rate, click rates, and click-through rate compared to previous months. However, this does not mean that your contacts and leads are engaging less with you, but rather the clicks/opens generated by interactions that are known to be NHI-related, are being filtered out from your statistics, giving you a more accurate view of your email performance.
Best Practices to avoid being targeted with NHIs
Secure Links
Since Click version 12.9, you now have a choice to use SSL Certificates for HTTPS Email CNAMEs to brand your links. You can also simply use the default *clickdimensions.com HTTPS out of the box. Either way, you should use HTTPS exclusively for all links. Emails with a mix of secure and non-secure tracking links appear to be disproportionately targeted, according to M3AAWG’s research. They report mixed link usage—e.g., a non-secure HTTP link directing to an advertiser from an HTTPS tracking link—seems to trigger the most unwanted behavior.
Segment your Data
Try to keep your engaged and non-engaged subscribers distinct when you are planning your sending domain, campaigns, workflows and automations.
Craft and Monitor your Content
Content quality is as important as always — not only what you are linking to, but also image to text ratio, Subject: line and Preheader choices and other factors. It was typically found that “aggressive” email marketing tends to lead to more NHIs.
Conserve your Reputation
Sender reputation has been found to play a significant role in the amount of NHIs. The amount of NHI for senders with highly engaged recipients is considerably lower. There are many steps you can take, but a top three would be:
- Gain clear consent from your subscribers, and abide by it
- Of course, don't Purchase or Rent lists
- Use Double Opt-In during sign-ups
If you don’t have the NHI filter enabled, you can always contact the support team - They can help you with that!