Why is Office365 automatically opening and clicking emails?
Michael Ko
Co-founder & CEO, Suped
Published 6 Jul 2025
Updated 17 Aug 2025
5 min read
Many email marketers have encountered a puzzling phenomenon: spikes in open and click rates, especially from recipient domains hosted on Microsoft Office 365. This can throw off campaign analytics and lead to confusion about actual subscriber engagement. While it might seem like your emails are being clicked by phantom users, there's a technical explanation behind this behavior.
The automatic opening and clicking of emails within Office 365 environments are predominantly due to the advanced security measures implemented by Microsoft. These systems proactively scan incoming emails for threats, which can artificially inflate your engagement metrics. Understanding this mechanism is crucial for accurate email performance analysis and maintaining good sender reputation.
Security scanners and why they act
The primary reason emails appear to be automatically opened and clicked within Office 365 (including Outlook.com and Hotmail) is the robust security filtering system, particularly Microsoft Defender for Office 365. These systems are designed to protect users from phishing, malware, and other malicious content before it even reaches the inbox.
When an email arrives, Microsoft's security filters automatically scan all elements within the message, including images, tracking pixels, and hyperlinks. This pre-scanning occurs in a sandboxed environment, meaning the email is opened and its links are clicked by an automated system, not a human recipient.
This preventative measure is designed to detect and neutralize threats before they can reach the end-user. If a malicious link is found, it can be neutralized or the email can be quarantined, protecting the user. This behavior is common across many large email providers and corporate security solutions, not just Microsoft.
Understanding the security scanning process
Email security solutions, like Microsoft's Defender for Office 365, employ advanced techniques to analyze incoming mail. This includes:
URL detonation: Links within the email are opened in a sandboxed environment to check for malicious redirects or content.
Attachment sandboxing: Attachments are opened and analyzed in isolation to ensure they don't contain malware.
Content analysis: The email content itself is scanned for suspicious patterns, phishing indicators, or other threats.
This proactive approach generates false opens and clicks, as the system simulates user interaction to test the email's safety. For more information on how security solutions click hyperlinks, refer to our guide on Do email security software solutions click hyperlinks in emails.
Impact on email analytics and deliverability
One of the most significant consequences of these automated interactions is the distortion of your email marketing metrics. An inflated open rate might lead you to believe your campaigns are performing better than they actually are, obscuring the true engagement of your human subscribers.
Similarly, false clicks can complicate the analysis of your click-through rates, making it challenging to assess the effectiveness of your calls to action. This can affect strategic decisions based on engagement metrics, leading to misinterpretations of campaign success or audience behavior.
While these automated actions generally don't block your emails outright, they can create a misleading picture of your deliverability. It's important to differentiate between genuine recipient engagement and these security-driven interactions. You can read more about why automated clicks happen on Office 365 hosted domains in our detailed guide.
True engagement metrics
Actual opens: Reflects human interaction, indicating content resonance and inbox placement.
Genuine clicks: Shows user interest in your offers, leading to conversions.
Conversion rates: Accurate measure of marketing ROI directly tied to human actions.
Observed metrics with scanning
Inflated opens: Includes bot activity, making actual engagement harder to discern.
Misleading clicks: Incorporates security clicks, distorting analysis of call-to-action effectiveness.
Skewed ROI: Difficulty in accurately attributing conversions to email marketing efforts.
Identifying and managing automated interactions
While you cannot prevent Microsoft's security systems from pre-scanning emails, you can implement strategies to identify and account for these automated interactions. This involves careful data analysis and adjusting your understanding of email metrics.
Look for specific patterns in your email data. Automated opens and clicks often come from specific IP ranges, occur immediately after sending, or originate from distinct user agents. By segmenting your data and filtering out known bot activity, you can get a clearer picture of your human engagement. You can learn more about this in our guide on identifying and handling bot clicks and opens.
It's also essential to maintain a strong sender reputation. Even with automated scanning, good sender practices ensure your emails reach the primary inbox rather than being diverted to spam or a blocklist (or blacklist). This includes proper authentication protocols like DMARC, SPF, and DKIM, and consistently sending valuable content to engaged subscribers.
For specific issues, like preventing Microsoft Defender from triggering unwanted one-click unsubscribes, understanding the technical aspects of email headers and how security systems interact with them is key. Our article on preventing Microsoft Defender from triggering unwanted unsubscribes offers targeted advice.
Characteristic
Description
IP ranges
Automated systems often originate from well-known Microsoft IP addresses or ranges associated with cloud services.
User agents
Bot activity can be identified by generic or specific user agent strings, distinct from typical browser or email client agents.
Click patterns
Automated clicks often occur very rapidly or click all links simultaneously, which is unnatural for human interaction.
Timestamps
Opens and clicks might register before the email has a realistic chance to be opened by a human, or during off-peak hours.
Example of a common user agent string for Office 365 security scanning
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36 (OutlookSafeLink)
Navigating the landscape of automated email interactions
The automatic opening and clicking of emails by Office 365 (and other similar security systems) is a standard security practice designed to protect recipients from threats. While this behavior can skew your email engagement metrics, it's a reality of modern email security.
The key is not to fight this behavior, but to understand it and adapt your analytics accordingly. By recognizing the signs of automated interactions and focusing on metrics that reflect true human engagement, you can make more informed decisions about your email marketing strategy and maintain strong email deliverability.
Views from the trenches
Best practices
Always segment your email data to identify and filter out automated opens and clicks for clearer insights.
Focus on downstream metrics like conversions and actual website visits to measure true campaign performance.
Regularly monitor your sender reputation and ensure strong email authentication (SPF, DKIM, DMARC) for better deliverability.
Test your emails across various clients and security solutions to anticipate potential automated interactions.
Common pitfalls
Over-relying on reported open and click rates without accounting for security scanner activity leads to misinterpretation.
Ignoring bot traffic, which can inflate costs for analytics platforms that charge based on interaction volume.
Implementing aggressive one-click unsubscribe links in the email body that security scanners might trigger accidentally.
Failing to adapt reporting to distinguish between genuine engagement and automated security checks.
Expert tips
Utilize unique tracking parameters for different email campaigns to better differentiate human activity from automated scans.
Analyze user agent strings and IP addresses in your logs to identify common security scanner patterns and filter them out.
Consider engaging with recipients directly to verify engagement if you see highly unusual patterns in your metrics.
Regularly review Microsoft's documentation for updates on how their security features impact email deliverability and tracking.
Marketer view
Marketer from Email Geeks says this automatic opening and clicking by Office 365 is a very common occurrence in the enterprise and B2B email space, and it's becoming more prevalent.
2024-05-21 - Email Geeks
Marketer view
Marketer from Email Geeks says there isn't much to do about automated opens and clicks, as it is an anti-defense mechanism, but suggests cleaning data and filtering out bot activity.
Microsoft Office 365. This can throw off campaign analytics and lead to confusion about actual subscriber engagement. While it might seem like your emails are being clicked by phantom users, there's a technical explanation behind this behavior.
