Do email tracking pixels affect deliverability?

Key findings

• Reputation Impact: Shared tracking URLs, especially those used by multiple senders or associated with low-quality bulk email tools, can carry a shared negative reputation that affects deliverability.
• Configuration Criticality: Messed-up CNAME branding for tracking pixels is a common issue that can directly lead to deliverability problems or flagging as spam. Proper setup of branded tracking domains is crucial.
• Security and Privacy: Using TLS/SSL for tracking pixels is essential for security. Additionally, compliance with regulations like GDPR requires explicit permission to track email opens in certain regions, potentially impacting how and when pixels can be used. For more on this, read how GDPR affects email deliverability.
• Limited Direct Impact: Many experts suggest that a tracking image from a reputable or neutral ESP or provider, when properly configured, should not inherently cause a significant impact on deliverability by itself.
• Sender Behavior Over Pixel: The overall sending patterns, content quality, and recipient engagement play a much larger role in deliverability than the mere presence of a tracking pixel.

Key considerations

• Branded Tracking: Always set up branded tracking domains (CNAMEs) for your email tracking pixels to avoid inheriting negative reputations from shared tracking links. This also applies to image hosting, as discussed in our guide on custom domains for image hosting.
• Reputation Management: Monitor the reputation of your tracking domains, just as you would your sending domains. Issues with these can contribute to blocklisting. To understand more about this, check out our guide on how email blacklists actually work.
• Gradual Rollout: When introducing tracking pixels, consider a slow rollout to observe any potential impacts on deliverability and make adjustments as needed.
• Transparency and Trust: Be transparent with recipients about data collection practices, especially for cold outreach. Some email clients may block pixels or flag messages if they perceive aggressive or unsolicited tracking. Sparkle.io provides additional insights into email tracking pixels in 2025.

Key opinions

• Branding is Key: Many marketers emphasize that deliverability issues with tracking pixels usually arise when CNAME branding is misconfigured or completely absent. Setting up branded URLs is a recommended safety measure.
• Shared Reputation Risk: If tracking links are shared across many senders, especially through cold email tools, they can accumulate a negative shared reputation, leading to messages being flagged as spam or even rejected.
• GDPR Compliance: For emails sent to recipients in the EU, marketers must secure explicit permission to use tracking pixels, a critical compliance point under GDPR.
• Limited Direct Pixel Impact: Some marketers suggest that reputable ESPs' tracking pixels (when properly configured) have minimal to no direct negative impact on deliverability. The issues are more often related to the domain's reputation or sender behavior.
• Testing is Crucial: Implementing tracking pixels requires careful testing, with some marketers recommending a phased rollout to monitor deliverability effects before full deployment.

Key considerations

• Distinguish Tracking Types: Marketers should understand the difference between tracking pixels and link tracking, as their impact on deliverability can vary. Our article on link shorteners and ESP click tracking provides further context.
• HTTPS/SSL for Pixels: Ensure that tracking pixels are served over HTTPS/SSL to maintain trust and security. This is a general best practice for all email elements.
• Audience and Use Case: Consider the type of email being sent. Cold emails with aggressive tracking are more likely to face issues than consent-based marketing emails. Learn more about unsolicited link building and sales emails.
• Monitor Deliverability: Continuously monitor inbox placement and overall deliverability metrics when implementing any new tracking features. Email on Acid offers guidance on email tracking pixels and their usage.

Key opinions

• Domain Reputation is Paramount: Experts emphasize that it is the reputation of the domain hosting the tracking pixel, rather than the pixel itself, that typically influences deliverability. Shared domains with poor reputations can lead to issues.
• Spam Filter Nuance: Mailbox providers are sophisticated enough to differentiate between legitimate tracking pixels and those used in malicious or spammy contexts. A simple pixel from a trusted source is unlikely to trigger spam filters on its own.
• Engagement Signals: While pixels track opens, experts note that true engagement signals, such as clicks, replies, and emails not marked as spam, hold more weight with ISPs. Pixels are becoming less reliable for engagement measurement, as discussed in how to accurately measure email open rates.
• Stealth Pixels: Mailbox providers are aware of tracking pixels (including invisible ones) and their purpose. Attempts to 'hide' tracking can sometimes backfire and negatively affect sender reputation.

Key considerations

• Context Matters: The same tracking pixel might behave differently depending on the overall email context, including sender reputation, content, and list quality. A pixel in a legitimate marketing email is treated differently from one in a phishing attempt.
• Avoiding Blocklists: Ensure your tracking domains are not on any email blocklists (or blacklists). Regular checks of your email domain reputation are advisable.
• Privacy Initiatives: Be aware of increasing privacy features in email clients (like Apple Mail Privacy Protection) that render pixel-based open tracking unreliable. This shift diminishes the utility of pixels for engagement measurement.
• Focus on Core Deliverability: While tracking pixels are a component, experts advise prioritizing fundamental deliverability factors such as email authentication (SPF, DKIM, DMARC), content quality, and list hygiene. Read more on reputation factors for email deliverability.

Key findings

• Functionality: A tracking pixel is typically a 1x1 transparent image embedded in an email. When the email is opened and images are loaded, a request is sent to a server, registering the open and often capturing information like IP address, time, and device.
• Image Blocking: Many email clients, for privacy or security reasons, block images by default. This means tracking pixels may not always load, affecting open rate accuracy without necessarily indicating a deliverability issue.
• Third-Party Domains: Pixels often load from a third-party domain (e.g., your ESP's tracking domain or a CDN for images). The reputation of this domain can be a factor for spam filters. This is why tracking URL subdomain alignment is important.
• Gmail's Handling: Gmail, in particular, caches images on its own servers, effectively loading the pixel once and serving it from Google's domain. This can obscure the original IP and location, impacting traditional pixel tracking accuracy.

Key considerations

• HTTPS Usage: Documentation often advises using HTTPS for all image and tracking pixel URLs to ensure secure content delivery and avoid mixed content warnings, which can impact user trust and potentially spam filtering. Learn more about HTTPS/SSL for email links and images.
• Minimizing Pixel Count: While not explicitly stated as a direct deliverability risk, some sources suggest that embedding multiple tracking pixels can make an email look suspicious and potentially break the email rendering in some clients.
• Content Ratio: Official best practices often recommend a healthy text-to-image ratio. Excessive reliance on images without sufficient text (which includes a tracking pixel being the only or dominant image) can trigger spam filters. For insights into this, check our article on protecting deliverability for image-only emails.
• Evolving Tracking Landscape: Marketers should be aware that the effectiveness of tracking pixels is evolving. Documentation from platforms like Medium highlight how Gmail's handling of open tracking is evolving, suggesting a move towards more privacy-focused approaches.