Does Apple Mail Privacy Protection pre-fetch images from spam folders or only the inbox?

The impact of Apple's Mail Privacy Protection (MPP) on email open rates is a complex issue with varied perspectives. While some experts suggest MPP only works from the inbox and that Apple doesn't control spam folder placement, the predominant view, supported by Apple's own documentation and numerous email marketing platforms, indicates that MPP preloads email content regardless of whether it lands in the inbox or spam folder. This pre-loading significantly affects the accuracy of open rates, making them less reliable for gauging user engagement. As a result, email marketers are widely advised to shift their focus to alternative metrics like click-through rates and conversions. Additionally, MPP's interaction with VPNs can further complicate image loading, even for emails in the inbox, adding another layer of complexity to the data landscape.

The introduction of Apple's Mail Privacy Protection (MPP) has significantly impacted the reliability of open rate metrics in email marketing. MPP pre-loads images, including tracking pixels, regardless of whether an email is actually opened by the recipient. This pre-loading affects open rate accuracy, making it harder to track genuine engagement. While many sources don't specifically address pre-fetching from the spam folder versus the inbox, the implication is that pre-fetching occurs regardless of placement. As a result, email marketers are advised to shift their focus towards alternative metrics like click-through rates and conversions to gauge campaign performance more accurately.

The question of whether Apple Mail Privacy Protection (MPP) pre-fetches images from spam folders or only the inbox receives varied responses. One perspective emphasizes that MPP only functions from the inbox, with the Apple spam folder being user-centric, not globally controlled by Apple. Another source highlights that Apple Mail's behavior depends on preceding events; images are unlikely to be fetched if an email is placed in the Junk folder, though the mail provider might have already pre-fetched them. Additionally, MPP's interaction with VPNs can further complicate image loading, even for emails in the inbox. Conversely, another source asserts that MPP preloads email content regardless of inbox or spam folder placement, diminishing the reliability of traditional open rates. These conflicting views suggest a complex interplay of factors influencing MPP's behavior.

According to documentation from Apple Developer, Campaign Monitor, Sendinblue, and Oracle, Apple's Mail Privacy Protection (MPP) pre-loads remote content, including tracking pixels, through a proxy server. This pre-loading of images occurs regardless of whether an email lands in the inbox or spam folder. As a result, the reliability of open rates as a metric for gauging email engagement is significantly reduced, and marketers are advised to leverage alternative metrics to assess campaign performance.