What “Exclude-Prefetch-Activity” Actually Means
What Internal Comms Leaders Need to Understand
Modern internal email analytics are not as straightforward as they once were. If you’re reporting to leadership using open rates alone — especially in a Microsoft 365 corporate environment — you’re likely working with distorted data.
Understanding exclude-prefetch-activity is now fundamental to providing credible, strategic insight.
The technical problem
Email engagement metrics (like open rates) have traditionally been tracked using an invisible tracking pixel — when the pixel loads, that signals an “open.” But modern email clients and network systems (e.g., Apple Mail Privacy Protection, Microsoft 365 Protection and Defender Layers, Gmail prefetching, spam/security scanners) will automatically load those pixels before a person ever sees the email.
This happens because:
- Email security systems scan incoming emails for threats
- Corporate filtering layers inspect links and attachments
- Some email clients fetch external content automatically
- Privacy protection systems mask user behaviour
In Microsoft 365 environments — which dominate corporate organisations — emails pass through Exchange Online Protection and Microsoft Defender layers. These systems may:
- Preload content
- Inspect links via Safe Links
- Trigger tracking pixels during automated scanning
The result?
- Open rates can be artificially inflated
- Engagement may appear stronger than it truly is
This is known as prefetch activity — automated system activity recorded as human interaction.
Platforms that offer exclude-prefetch-activity attempt to filter out this non-human behaviour so reported engagement reflects genuine user interaction.
For a deeper explanation of how Outlook and Microsoft 365 environments contribute to this effect, see the FAQ section below.
Why excluding prefetch activity matters
When you exclude prefetch or bot opens:
- Reported open rates are lower but more accurate.
- You reduce the risk of false positives — thinking a message was impactful when it wasn’t.
- Benchmarks become more reliable over time — because they’re based on human interactions, not automated fetches.
In other words, it’s better to see true relevance even if reach appears lower.
Why This Matters for Internal Comms
Internal communications teams constantly balance two competing needs:
Reach
“How many people received our message?”
Relevance
“How many people actually engaged meaningfully?”
Prefetch distortion primarily affects relevance metrics — especially opens. If you present inflated open rates to leadership:
- You may overstate message impact
- You risk building strategy on unreliable signals
- You undermine long-term credibility
Excluding prefetch activity protects your insight integrity — even if reported open rates drop.
Lower but honest engagement data is far more valuable than impressive but artificial metrics.
For additional insights into strategic internal communications, visit our internal communications resources page.
How NewZapp Approaches These Challenges
In our 2021 article Is your Email Communications Provider lying to you? We outline how some providers report significantly inflated engagement due to bot and automated activity.
In one example, another platform reported over 65,000 clicks — while NewZapp’s filtered data showed under 5,000 genuine interactions.
The difference?
NewZapp removes:
- Spambot clicks
- Automated security interactions
- Non-human engagement signals
✔ Filtering out non-human interaction
NewZapp actively detects and removes spambot or automated clicks — the kinds of activity that inflate metrics on other platforms. In the blog example, one provider reported ~65k clicks, while NewZapp’s cleaned data showed ~4.9k — and NewZapp’s numbers were true measures of engagement.
This matters because:
- You aren’t rewarded for fake engagement.
- You can tie internal emails to real action, not phantom clicks.
✔ Accurate, honest reporting over vanity metrics
Rather than showcasing artificially high metrics, NewZapp focuses on safe, accurate analytics you can trust to inform strategy — especially important when you’re reporting to leadership or the board.
✔ Deliverability monitoring
NewZapp also includes tracking of how reliably emails are delivered to recipients, reducing the ambiguity between was this message delivered and was this message engaged with — a key distinction in internal comms.
Delivery metrics help validate reach — and how email deliverability impacts inbox placement is foundational to ensuring your message actually arrives and can be accurately interpreted (see email deliverability issues and fixes).
This ensures that when you report engagement to stakeholders, you’re reporting real behaviour, not system noise. For teams operating in Microsoft 365 corporate environments, this distinction is critical.
Practical Takeaways for Internal Comms Leaders
When you brief stakeholders, here are the core points to emphasise:
🔹 Always look beyond open rates
Open rates are less trustworthy now unless prefetch and bot activity are excluded. Focus on:
- Click behaviour
- Secondary actions (survey completions, intranet visits)
- Conversion signals
These are stronger evidence of relevance and engagement.
🔹 Be transparent about data limitations
Explain that changes in email client behaviour (privacy protections, proxying) make traditional metrics noisy — but modern platforms can reduce that noise.
🔹 Tie metrics to outcomes
Reach is necessary (everyone got the message). Relevance is transformational (people acted on it). Accurate exclusion of prefetch activity helps you evaluate the latter more reliably.
🔹 Benchmark responsibly
Comparing internal email programmes requires consistent methodologies — especially when some tools include prefetch opens and others (like NewZapp) exclude them. Clarify methodology when presenting to leadership
Bottom Line for Internal Comms
Exclude-prefetch-activity is no longer a niche technical setting — it’s central to credible reporting in modern internal communications. Platforms that account for and exclude automated opens/clicks give you true insight into employee engagement — helping you:
✔ Report honestly to leaders
✔ Avoid chasing vanity metrics
✔ Align communications strategy with real behaviour
✔ Make better decisions based on solid evidence
If you position your analytics this way, leadership won’t just see reach — they’ll understand real organisational impact.
Frequently Asked Questions
How Does Microsoft 365 (M365) and Outlook Affect Email Open and Click Tracking?
In corporate Microsoft 365 environments, email is processed by multiple security layers before it reaches an employee.
These often include:
- Exchange Online Protection (EOP)
- Microsoft Defender for Office 365
- Safe Links URL scanning
- Automated attachment sandboxing
During this process, security systems may:
- Retrieve tracking pixels
- Activate or inspect links
- Trigger activity that appears as opens or clicks
All of this can trigger:
- False opens
- Automated link activations
- Inflated engagement reporting
This behaviour is automated and security-driven — not employee-driven.
As a result, some reported engagement metrics in Outlook environments may reflect system inspection rather than genuine human interaction.
In large corporate environments, especially those with strict cybersecurity policies, a significant proportion of open activity can be system-generated rather than human.
This is precisely why exclude-prefetch-activity filtering is essential for internal comms analytics.
Without it, you may believe your message resonated — when in reality it was simply scanned.
What Is Prefetch Activity in Email Marketing?
Prefetch activity refers to automated systems loading email content — including tracking pixels or links — before a human opens the message.
This may be triggered by:
- Security scanning tools
- Privacy protection systems
- Email client preloading behaviour
When prefetch activity is not excluded, it can inflate open rates and distort engagement reporting.
What Does “Exclude-Prefetch-Activity” Mean in a Bulk Email Platform?
Exclude-prefetch-activity is a filtering mechanism that removes automated, non-human interactions from engagement reports.
This includes:
- Security bot opens
- Automated link scans
- Spambot click activity
The goal is to ensure reported engagement reflects genuine human behaviour rather than system-generated events.
Why Are Email Open Rates Unreliable in Corporate Environments?
Open rates rely on tracking pixels being loaded.
In corporate environments — particularly those using Microsoft 365 — pixels may be triggered by:
- Email security gateways
- Link inspection tools
- Automated threat detection systems
This means an “open” does not always mean the email was read.
Open rates should be interpreted as directional visibility metrics, not proof of engagement.
Can Microsoft Defender or Safe Links Cause False Clicks?
Yes.
Microsoft Defender’s Safe Links feature rewrites and checks URLs for malicious content. During this inspection process, links may be activated automatically.
Some email platforms record this as a click, even though no employee interacted with the message.
Platforms that filter automated activity reduce the likelihood of these false-positive click reports.
How Can Internal Comms Teams Measure Genuine Email Engagement?
To measure meaningful engagement, internal comms teams should focus on:
- Unique human click-through rates
- CTA interactions
- Survey submissions
- Intranet visits
- Behavioural follow-through
These signals demonstrate relevance and intent — not just visibility.
What Is the Difference Between Email Reach and Relevance?
Reach measures how many employees received the message.
Relevance measures how many employees meaningfully engaged with it.
Prefetch activity affects relevance metrics more than reach metrics.
Separating these two concepts improves the quality of insight provided to leadership.
Why Do Some Email Platforms Report Higher Engagement Than Others?
Differences in engagement reporting often come down to filtering standards.
Platforms that do not exclude:
- Bot clicks
- Security scans
- Prefetch pixel loads
may report significantly higher open and click rates.
Higher numbers do not necessarily mean better performance — they may reflect less stringent filtering.
Does Excluding Prefetch Activity Lower Engagement Rates?
Yes — but it improves accuracy.
When automated activity is removed:
- Open rates may decrease
- Click counts may appear lower
However, the remaining data more accurately reflects human interaction, which is more valuable for strategic decision-making.
Why Is Accurate Email Reporting Important for Leadership Decision-Making?
Leadership relies on internal comms data to assess:
- Message effectiveness
- Channel performance
- Workforce engagement
- Behavioural impact
If metrics are inflated by automated activity, strategic decisions may be based on misleading signals.
Accurate, filtered reporting enables:
- Realistic benchmarking
- Credible performance analysis
- More effective communications planning
Honest data builds long-term trust — internally and organisationally.
Speak with us and find out more
