What is Apple Mail Privacy Protection (MPP) and how does it work?

Apple Mail Privacy Protection (MPP) is a feature within the native Apple Mail app on macOS Monterey, iOS 15, and iPadOS 15. It works by routing email content through proxy servers to hide IP addresses and pre-fetch all remote content, making traditional open rate tracking unreliable.

Will Apple Mail Privacy Protection affect Outlook or other third-party email clients on Mac OS Monterey?

No, Apple Mail Privacy Protection (MPP) itself does not directly affect Microsoft Outlook or other third-party email clients (like Gmail or Yahoo Mail ) when used on Apple devices. These apps handle email rendering and content fetching independently of Apple's Mail app privacy features.

How does Apple Private Relay differ from MPP, and does it impact Outlook on Mac OS Monterey?

Apple Private Relay is a separate iCloud+ feature that hides a user's IP address for all outgoing internet traffic from their Apple device, including traffic from third-party email clients like Outlook. If a user has Private Relay enabled, their IP will be masked, but this is due to Private Relay, not MPP directly.

What are the key implications of Apple's privacy features for email marketers?

Email marketers should shift their focus from open rates to other engagement metrics like click-through rates, website visits, and conversions. Ensuring strong email authentication ( SPF, DKIM, and DMARC ) and maintaining good sender reputation are also increasingly important for deliverability.

Will Apple Mail Privacy Protection affect Mac OS Monterey users and Outlook? - Technical - Email deliverability - Knowledge base

Q: Does Apple Mail Privacy Protection affect Mac OS Monterey users?

Yes, MPP is available to macOS Monterey users who opt-in to the feature within the Apple Mail application settings. If enabled, email open tracking from the native Mail app on Mac will be affected, similar to iOS and iPadOS devices.

When Apple announced Mail Privacy Protection (MPP), it marked a significant shift in how email activity is tracked, particularly for users of their native Mail app. This feature, introduced with iOS 15, iPadOS 15, and macOS Monterey, aims to give users more control over their data by preventing senders from using tracking pixels to collect information like IP addresses and open times. Many email senders and marketers immediately wondered about the full extent of its impact: would it affect users across all Apple devices, and crucially, would it extend to third-party email clients like Microsoft Outlook when used on a Mac with the Monterey operating system?

The answer, while straightforward for MPP itself, becomes a bit more nuanced when considering Apple's broader privacy features like Private Relay. Understanding these distinctions is key to comprehending the real impact on your email metrics and deliverability strategy. Let's delve into how MPP works, its specific reach on Mac OS Monterey, and whether Outlook users are truly affected by its privacy measures.

Understanding Apple Mail Privacy Protection (MPP)

Mail Privacy Protection (MPP) is a feature specifically designed for the Apple Mail application. Its primary goal is to hide a user's IP address and pre-load all remote content (including tracking pixels) in an email, regardless of whether the user actually opens or interacts with the email. This pre-loading happens in the background via proxy servers, which means a false open signal is sent to email senders, making traditional open rate tracking unreliable for Apple Mail users. For more details on this, you can review Apple Mail Privacy Protection documentation.

This functionality is deeply integrated into the Mail application itself. When a user updates to a compatible operating system, such as iOS 15, iPadOS 15, or macOS Monterey, they are prompted to enable MPP. If enabled, it masks their interaction with the email, ensuring that email senders cannot use the open pixel to gather data about their behavior or location. This has significantly altered how marketers measure engagement and how they estimate real open rates.

What mail privacy protection does

IP Address Masking: Hides the user's IP address from email senders, preventing location tracking and linkage to other online activities.
Remote Content Pre-Loading: Downloads all remote content, including tracking pixels, through Apple's proxy servers as soon as the email arrives in the inbox (or when the Mail app is opened), regardless of whether the user actually opens it. This generates false open signals.
No User Engagement Data: Senders lose the ability to accurately track when and if an email was truly opened by the recipient, impacting traditional email marketing metrics.

MPP's reach on macos Monterey

Yes, Apple Mail Privacy Protection is very much a feature available to macOS Monterey users who use the native Apple Mail application. When macOS Monterey was released, MPP was included as an opt-in privacy feature alongside iOS 15 and iPadOS 15. This means that if a user updates their Mac to Monterey (or a later version of macOS) and chooses to enable Mail Privacy Protection within the Mail app settings, their email open activity will be anonymized, just as it is on iPhones and iPads.

The key here is that MPP applies specifically to the native Apple Mail application on macOS. It's not a system-wide privacy setting that affects all email clients universally. Its inclusion on Mac mirrors the privacy enhancements Apple rolled out across its mobile devices, reflecting a broader commitment to user data protection. For marketers, this means that a significant portion of their Mac-using audience (those using Apple Mail) will also contribute to the inflated open rates and obscured IP data.

Outlook and other third-party clients

This is where the distinction becomes crucial. Apple Mail Privacy Protection (MPP) itself does not directly affect email clients like Microsoft Outlook, Gmail, or any other third-party email app running on macOS Monterey (or iOS/iPadOS). These applications use their own methods for rendering emails and fetching remote content. They do not route their email traffic through Apple's MPP proxy servers.

If a user on macOS Monterey opens an email in Outlook, the open tracking pixel behaves as it always has. The sender will receive an accurate open signal and the user's actual IP address (unless other system-level privacy features are active). So, for marketers, data from Outlook users on Mac OS Monterey should remain reliable for open rate calculations, as long as those users are not also employing Apple Private Relay, which is a different privacy feature altogether.

Apple Mail Privacy Protection (MPP)

Scope: Applies only to Apple Mail app users.
Function: Hides IP and pre-fetches email content (tracking pixels).
Impact on Metrics: Inflates open rates for Apple Mail users, making them unreliable.
Requirement: Opt-in setting within the Mail app.

Apple Private Relay (iCloud+ feature)

Scope: Affects all outgoing internet traffic from the device.
Function: Hides IP address by routing traffic through two separate internet relays.
Impact on Metrics: Prevents IP-based tracking across all apps, including Outlook and web browsers.
Requirement: Paid iCloud+ subscription.

Private relay: the wider impact

While MPP specifically targets the Apple Mail app, Apple Private Relay is a different beast entirely. Private Relay is an iCloud+ (paid) feature that acts like a VPN-ish service, obscuring a user's IP address for all internet traffic originating from their Apple device, regardless of the application being used. This means that if a user on macOS Monterey has Private Relay enabled, their IP address will be hidden from email senders, even when they open emails in Outlook, Chrome, or any other application that accesses the internet.

The distinction is crucial: MPP focuses on email privacy within the Mail app, while Private Relay offers a more comprehensive, system-wide IP masking. As one expert noted, MPP uses the same underlying infrastructure as Private Relay, leading to similar traffic patterns in terms of IP masking. Therefore, while Outlook itself isn't impacted by MPP, a user's choice to enable Private Relay will indeed affect the IP address data collected from their Outlook usage on a Mac.

Email client	Operating system	MPP impact	Private relay impact
Apple Mail	iOS/iPadOS/macOS	Yes (false opens, IP hidden)	Yes (IP hidden, even more robust)
Outlook	iOS/iPadOS/macOS	No (email content/opens)	Yes (IP hidden if Private Relay enabled)
Gmail App	iOS/iPadOS/macOS	No (email content/opens)	Yes (IP hidden if Private Relay enabled)
Webmail (Browser)	Any OS	No	Yes (if Private Relay enabled on Apple device)

Adapting your email strategy

For email marketers, the introduction of MPP and the prevalence of Private Relay users means a necessary evolution in strategy. Relying solely on open rates as a primary metric for campaign performance is no longer viable, especially if a significant portion of your audience uses Apple devices. We also see this trend with Gmail machine opens.

Instead, focus should shift towards metrics that truly reflect engagement and conversion, such as click-through rates, website visits, and direct conversions. This requires more compelling calls to action within the email content and a greater emphasis on list hygiene and sender reputation. Ensuring proper email authentication with SPF, DKIM, and DMARC becomes even more critical for deliverability, as inbox providers will increasingly rely on these signals over open rates to gauge sender trustworthiness.

Additionally, consider implementing strategies like IP warmup adjustments that account for the changing landscape of email metrics. The goal is to build a robust deliverability program that isn't overly dependent on metrics that Apple (and potentially other providers) are making obsolete for privacy reasons.

Navigating the evolving email privacy landscape

Understanding the nuances of Apple Mail Privacy Protection and Private Relay is essential for anyone sending emails. While MPP specifically impacts those using the native Apple Mail app on macOS Monterey (and other Apple operating systems), it does not directly extend its open-tracking anonymization to third-party clients like Outlook. However, the broader system-wide IP masking offered by Apple Private Relay can indeed affect Outlook users by obscuring their IP address, a subtle but important distinction.

As the email landscape continues to prioritize user privacy, adapting your measurement and deliverability strategies to rely less on traditional open rate metrics and more on tangible engagement signals is paramount. Focusing on a healthy sending reputation, strong email authentication, and compelling content will ensure your messages continue to reach and resonate with your audience, regardless of their chosen email client or privacy settings.

Views from the trenches

Best practices

Focus on engagement metrics beyond open rates, such as clicks, conversions, and website visits, as these reflect true user interest.

Regularly clean your email lists to remove inactive subscribers, improving overall deliverability and reducing bounces.

Prioritize email authentication protocols (SPF, DKIM, DMARC) to build and maintain sender reputation.

Segment your audience based on behavior (e.g., click activity) rather than just open data for more targeted campaigns.

Common pitfalls

Over-reliance on open rates as the sole measure of email campaign success, leading to inaccurate performance assessments.

Failing to differentiate between Mail Privacy Protection and Private Relay, misinterpreting data for third-party clients.

Neglecting to update email deliverability strategies to account for the increasing adoption of privacy features.

Not monitoring other deliverability indicators, such as bounce rates and spam complaints, to assess email health.

Expert tips

Consider a shift to a 'zero-party data' approach, directly asking subscribers for their preferences.

Utilize unique links or coupon codes in emails to track conversions that bypass traditional open tracking.

Analyze engagement patterns over time to identify trends that may indicate a shift towards privacy-enhanced environments.

Educate your team on the distinctions between various Apple privacy features to ensure accurate reporting and strategy.

Expert view

Expert from Email Geeks says that Mail Privacy Protection is included as a feature in the new macOS Monterey as well as iOS devices.

2021-10-14 - Email Geeks

Expert view

Expert from Email Geeks says that on Monterey, you will observe traffic from Apple proxies for most Apple Mail users, and also from clients like Outlook on Mac if the user has enabled the Private Relay feature.

2021-10-14 - Email Geeks