Will Apple MPP or Gmail machine opens occur on emails delivered to spam?

Summary

The consensus regarding whether Apple MPP or Gmail machine opens occur on emails delivered to spam is mixed. Some evidence suggests that MPP and Gmail machine opens are unlikely to trigger in the spam folder because content isn't downloaded there. However, other evidence indicates that image caching, image proxies, and security protocols process content before delivery, potentially leading to open tracking even if the email lands in spam. Factors like pre-fetching technologies, the sophistication of filtering mechanisms, and whether or not content is loaded before final classification play a significant role in determining whether an open is registered.

Key findings

  • Content Download Variance: Some suggest content isn't downloaded in spam, preventing MPP/Gmail opens; others claim it is loaded beforehand.
  • Pre-delivery Processing: Image caching, proxies, and security protocols may trigger opens prior to spam filtering.
  • Technology Influence: Pre-fetching technologies can inflate open rates even if an email ends up in spam.
  • Reliability Issues: Pixel tracking's reliability is compromised due to MPP, filters, and varied spam filter behaviors.

Key considerations

  • Filtering Complexity: Sophistication of filtering mechanisms influences whether opens are registered before or after spam classification.
  • MPP Timing: If MPP impacts metrics before spam filtering, even spam-bound emails could show skewed open rates.
  • Image Loading: Whether images load prior to delivery is a major determinant of whether an open event occurs, which can vary by provider and security setting.
  • Tracking Accuracy: Open tracking is generally unreliable and can be greatly affected by filtering, so data is not always accurate.

What email marketers say
11Marketer opinions

The question of whether Apple MPP or Gmail machine opens occur on emails delivered to spam elicits varied responses. Some sources suggest that because content is not downloaded in the spam folder, MPP and Gmail machine opens will not trigger. Others suggest that pre-fetching technologies and filtering mechanisms may influence open rates even if the email ends up in spam, thus potentially inflating open metrics or registering an open before the email is classified as spam. Pixel tracking may be unreliable due to these factors.

Key opinions

  • No content download: Some experts state that Apple MPP and Gmail machine opens typically do not occur in the spam folder because content is not downloaded there.
  • Prefetching influence: Prefetching technologies and filtering mechanisms can affect open rates, potentially causing opens to register even if the email is ultimately delivered to spam.
  • Image loading dependent: Open tracking's reliability hinges on image loading, which can happen even if the email is marked as spam.
  • Unreliable pixel tracking: Pixel tracking may be unreliable in general due to MPP and the inconsistent behaviour of spam filters.

Key considerations

  • Varying spam filter behavior: Spam filters are not created equal; some may trigger open pixels, while others isolate potentially harmful content, thus making any assumptions difficult.
  • MPP impact on spam: The impact of MPP might occur before spam filtering, potentially skewing open metrics even for emails that eventually land in spam.
  • Tracking inaccuracy: Email tracking can be affected by filtering, as emails in spam/junk folders may not load tracking pixels, leading to inaccurate open data.
  • Filtering Mechanisms: A thorough understanding of email filtering is critical to comprehending email deliverability and its impact on open rates.
Marketer view

Email marketer from EmailOnAcid states that pixel tracking is not reliable. This is due to many factors including MPP and filters.

April 2023 - EmailOnAcid
Marketer view

Email marketer from EmailGeek shares that MPP's impact is usually prior to spam filtering, meaning initial open metrics might be affected even if the email later lands in spam.

March 2021 - EmailGeek.com
Marketer view

Email marketer from Litmus explains that understanding filtering mechanisms is critical to understanding deliverability.

June 2023 - Litmus
Marketer view

Marketer from Email Geeks shares testing experience that Gmail open pixels only fire when the user opens an email in the inbox and not in the spam folder, using the Gmail machine http header.

July 2021 - Email Geeks
Marketer view

Email marketer from Mailjet shares that the open tracking can occur even if an email is marked as spam as open tracking is only dependent on image loading.

September 2024 - Mailjet
Marketer view

Email marketer from Reddit explains that while not all spam filters are created equal, most won't trigger open pixels, as that would defeat the purpose of isolating potentially harmful content.

May 2021 - Reddit
Marketer view

Email marketer from SendGrid shares that email tracking can be affected by filtering since emails in spam/junk folders might not load tracking pixels, which leads to inaccurate opens.

January 2022 - SendGrid
Marketer view

Email marketer from Reddit shares that Apple MPP does not trigger opens in the spam folder because the content is not downloaded there.

September 2021 - Reddit
Marketer view

Marketer from Email Geeks shares that Apple only prefetches opens for email that was sent to the inbox.

October 2022 - Email Geeks
Marketer view

Email marketer from CampaignMonitor explains that open rates can be influenced by pre-fetching technologies, even if the email ends up in spam, potentially inflating open metrics.

May 2024 - CampaignMonitor
Marketer view

Marketer from Email Geeks explains that content isn't downloaded when it hits the spam/junk folder, so no MPP or Gmail machine opens will occur there.

March 2024 - Email Geeks

What the experts say
2Expert opinions

Experts hold differing views on whether Apple MPP or Gmail machine opens occur on emails delivered to spam. SpamResource.com suggests that MPP's impact on open rates is unlikely within the spam folder because content is not loaded. Conversely, Word to the Wise argues that sophisticated filtering mechanisms load content before delivery, potentially registering opens before an email is classified as spam.

Key opinions

  • MPP unlikely in spam: SpamResource.com indicates that Apple MPP is unlikely to trigger opens within the spam folder due to content not being loaded there.
  • Filtering sophistication: Word to the Wise highlights that modern filtering systems load content before delivery, which could lead to opens being registered before an email reaches the spam folder.

Key considerations

  • Content Loading: Whether or not content is loaded before an email lands in the spam folder is a critical factor in determining if an open is registered.
  • Filtering mechanisms: The complexity of spam filters can affect whether an open is triggered before or after classification of the email as spam.
Expert view

Expert from Word to the Wise explains that email filtering is more sophisticated now with content loading before delivery. This leads to opens registering before it is sent to the spam folder.

October 2023 - Word to the Wise
Expert view

Expert from SpamResource.com explains that while MPP may affect overall open rates, it is unlikely to trigger opens in the spam folder itself due to content not being loaded.

April 2022 - SpamResource.com

What the documentation says
5Technical articles

Documentation from various sources indicates that Apple MPP or Gmail machine opens can potentially occur even on emails delivered to spam due to image caching, image proxies, security protocols, and filtering systems processing content before final delivery. This pre-delivery processing can trigger open tracking, regardless of the email's ultimate destination.

Key findings

  • Pre-delivery processing: Content processing, including image caching and scanning, often happens before the email is classified as spam.
  • Image proxy impact: Image proxies can fetch email content prior to inbox delivery, affecting open tracking even if the email is later marked as spam.
  • SCL Influence: While the Spam Confidence Level (SCL) determines spam placement, content processing and potential open triggers can still occur beforehand.
  • Security scans: Security protocols scan emails before final delivery, leading to potential 'open' events even if the email is eventually categorized as spam.
  • Filtering analysis: Filtering systems load images for analysis, which could register opens even for emails destined for the junk folder.

Key considerations

  • Open tracking inaccuracy: Open tracking can be inaccurate due to pre-delivery processing, potentially skewing email marketing metrics.
  • Deliverability impact: Understanding pre-delivery processing is important for managing email deliverability and ensuring messages reach the intended audience.
  • Influence of Image Loading: Image loading is a critical factor in open tracking and can be influenced by both email clients and spam filters.
Technical article

Documentation from SparkPost details that image proxies can fetch email content before it reaches the inbox, potentially affecting open tracking even if the email is eventually classified as spam.

September 2021 - SparkPost
Technical article

Documentation from IETF shares that security protocols often scan emails before final delivery, which could technically lead to an open 'event' even if the email is eventually classified as spam.

June 2021 - IETF
Technical article

Documentation from Microsoft explains that the Spam Confidence Level (SCL) determines if an email goes to spam, but content is still processed before delivery which could trigger opens.

September 2023 - Microsoft
Technical article

Documentation from AuthSMTP shares that filtering systems may load images for analysis, potentially registering opens even if the email is directed to the junk folder.

April 2022 - AuthSMTP
Technical article

Documentation from Google Developers explains that Gmail's image caching generally occurs before messages are filtered into spam, potentially affecting open tracking even if the email lands in the spam folder.

April 2021 - Google Developers