Will Apple MPP or Gmail machine opens occur on emails delivered to spam?
Summary
What email marketers say11Marketer opinions
Email marketer from EmailOnAcid states that pixel tracking is not reliable. This is due to many factors including MPP and filters.
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.
Email marketer from Litmus explains that understanding filtering mechanisms is critical to understanding deliverability.
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.
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.
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.
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.
Email marketer from Reddit shares that Apple MPP does not trigger opens in the spam folder because the content is not downloaded there.
Marketer from Email Geeks shares that Apple only prefetches opens for email that was sent to the inbox.
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.
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.
What the experts say2Expert opinions
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.
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.
What the documentation says5Technical articles
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.
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.
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.
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.
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.