Summary
Tracking pixels, small transparent images embedded in HTML emails, are used to track email opens. When an email is opened and the images are downloaded, the server hosting the pixel records the event. However, deleting the email also deletes the pixel. Modern email clients and browser extensions increasingly offer options to block remote images, preventing tracking. Apple's Mail Privacy Protection (MPP) pre-loads images and masks IP addresses, making open rates unreliable. Due to these challenges, marketers are advised to use alternative engagement metrics such as click-through rates, Google Analytics, personalized URLs, and unique offer codes. Transparency and providing opt-out options are also ethically important. The effectiveness of tracking pixels is diminishing due to user privacy controls.
Key findings
- Pixel Function: Tracking pixels are embedded images that track email opens via image downloads.
- Pixel Removal: Deleting an email removes its associated tracking pixel.
- Blocking Options: Email clients and browser extensions offer options to block image downloads and tracking.
- MPP Impact: Apple's MPP pre-loads images, leading to inaccurate open rate metrics.
- Alternative Metrics: Alternative metrics like click-through rates and Google Analytics offer better engagement insights.
Key considerations
- Privacy Compliance: Comply with privacy regulations and be transparent about tracking practices.
- Metric Reliability: Recognize the limitations of open rates as a reliable engagement metric.
- Data Accuracy: Understand that data from tracking pixels may be inaccurate due to privacy measures.
- Ethical Usage: Obtain consent before tracking and offer clear opt-out options to subscribers.
- Holistic Measurement: Use a combination of metrics for a comprehensive understanding of user behavior.
What email marketers say
9 marketer opinions
Tracking pixels are tiny, transparent images embedded in HTML emails to track when an email is opened. When the email is opened and images are downloaded, the server hosting the pixel registers the open. However, their reliability is decreasing due to increased privacy measures like image blocking by email clients and Apple's Mail Privacy Protection (MPP), which pre-loads images causing inflated open rates. Alternative methods for measuring engagement include click-through rates, Google Analytics tracking, personalized URLs, and unique offer codes. Transparency with subscribers regarding tracking and providing opt-out options are also important ethical considerations.
Key opinions
- Pixel Function: Tracking pixels are used to detect when an email is opened by tracking image downloads.
- Decreasing Reliability: Privacy measures and image blocking by email clients are making tracking pixels less reliable.
- Inflated Open Rates: Apple's Mail Privacy Protection (MPP) pre-loads images, leading to inaccurate and inflated open rates.
- Alternative Metrics: Click-through rates, Google Analytics tracking, personalized URLs, and unique offer codes are alternatives to track engagement.
Key considerations
- Privacy: Consider the ethical implications of using tracking pixels without explicit consent.
- Transparency: Be transparent with subscribers about tracking practices and offer opt-out options.
- Data Accuracy: Recognize that tracking pixel data may not be accurate due to privacy measures.
- Holistic Approach: Use a combination of metrics, not just open rates, to understand user behavior.
Marketer view
Email marketer from HubSpot suggests using click-through rates as an alternative way to measure email engagement when tracking pixels are unreliable. Encouraging recipients to click on links provides a more accurate measure of interest.
22 Sep 2021 - HubSpot
Marketer view
Email marketer from SuperOffice raises the ethical considerations of using tracking pixels without explicit consent. They suggest being transparent with subscribers about tracking practices and providing an option to opt-out.
29 Jul 2022 - SuperOffice
What the experts say
3 expert opinions
Deleting an email removes the tracking pixel associated with it. Email clients now offer options to block remote images by default, preventing tracking pixels from reporting back to senders. Increased privacy measures such as Apple's Mail Privacy Protection (MPP), which pre-loads images, present challenges in relying on open rates as a reliable metric.
Key opinions
- Pixel Removal: Deleting the email removes the tracking pixel.
- Image Blocking: Email clients can block remote images, preventing pixel tracking.
- MPP Impact: Apple's Mail Privacy Protection (MPP) pre-loads images, impacting open rate accuracy.
Key considerations
- Open Rate Reliability: Relying solely on open rates as a metric is increasingly unreliable.
- Privacy Settings: Users have increasing control over blocking tracking attempts.
- Alternative Metrics: Explore alternative email engagement metrics instead of relying on open rates.
Expert view
Expert from Email Geeks clarifies that deleting the email does delete the tracking pixel along with it.
26 Dec 2023 - Email Geeks
Expert view
Expert from Word to the Wise mentions the challenges in relying on open rates due to increased privacy measures like Apple's Mail Privacy Protection (MPP). This feature essentially pre-loads images, making it difficult to accurately track genuine opens.
30 Aug 2021 - Word to the Wise
What the documentation says
5 technical articles
Email tracking uses tiny, invisible images (tracking pixels) embedded in HTML emails. When an email recipient opens the email and their email client downloads the images, the server hosting the tracking pixel records the open. However, email clients like Outlook and Thunderbird have settings to block automatic image downloads and remote content, preventing tracking pixels from functioning unless explicitly allowed by the user. Apple's Mail Privacy Protection also prevents tracking by masking IP addresses and pre-loading remote content.
Key findings
- Pixel Embedding: Email tracking involves embedding tiny, invisible images in HTML emails.
- Image Download: Tracking occurs when the recipient's email client downloads the images.
- Blocking Settings: Email clients like Outlook and Thunderbird allow users to block automatic image downloads, preventing tracking.
- Mail Privacy Protection: Apple's Mail Privacy Protection masks IP addresses and pre-loads content to prevent tracking.
Key considerations
- User Control: Recipients have increasing control over preventing email tracking through privacy settings.
- Tracking Limitations: Email tracking may be limited or inaccurate due to client-side privacy protections.
- Privacy Awareness: Be aware of the impact of privacy features on email tracking effectiveness.
Technical article
Documentation from Litmus explains that email tracking works by embedding a tiny, invisible image (a tracking pixel) in HTML emails. When the recipient opens the email and their email client downloads the images, the server hosting the tracking pixel records the open. They note that if images are blocked, the open is not tracked.
11 Sep 2024 - Litmus
Technical article
Documentation from Sendinblue explains how recipients can disable image loading in their email clients to prevent tracking pixels from working. This effectively blocks the sender from knowing if the email has been opened.
22 Aug 2022 - Sendinblue
Are image-based emails a good practice, and what are the deliverability and accessibility implications?
Are image-only emails bad for deliverability?
Do images in emails affect deliverability?
Do ISPs re-fetch email tracking images, and what causes delayed email opens?
Do tracking pixels directly cause emails to be marked as spam?
Does Apple Mail Privacy Protection pre-fetch images from spam folders or only the inbox?
