The Impact of Apple Mail Privacy Protection (MPP)

[Rajat K]

What is Apple Mail Privacy Protection (MPP)?

Apple introduced Mail Privacy Protection (MPP) in September 2021 with iOS 15, iPadOS 15, and macOS Monterey. This feature is available to users of the Apple Mail app (not just iCloud users) and applies when accounts (like Gmail, Outlook, Yahoo, etc.) are configured in Apple Mail.

What Does MPP Actually Do?

MPP aims to protect user's privacy by masking certain data that senders typically track via email.

Preloads the Images Privately

• Most email marketers use tracking pixels, tiny 1*1 invisible images embedded in emails.
• These pixels are normally loaded only when a user opens the email. This is how typical opens are tracked.
• With MPP, Apple preloads all images, including tracking pixels, through Apple servers, regardless of whether the user opens the email or not.

Hides IP Address

• The email's images (including pixels) are fetched from a generic Apple IP address, not the user's real IP.
• This prevents marketers from determining the recipient's geographic location, device type, network or business info via IP lookup

Before MPP: What Email Marketers Could See from Apple Mail Users

When a user opened an email in Apple Mail before MPP, the following details were exposed to email service providers (ESPs) like Mailchimp, HubSpot, or Zoho Campaigns:

• IP Address: User's rough geographic location, ISP, and sometimes even business network
• Device Info: Device type, email client, OS
• Exact Time of Open: Allowed detailed engagement timelines
• Location Over Time: Allowed geo-fencing or time-zone targeting

Example: The ESPs before MPP logged

Opened in iPhone Mail | 6:34 PM | San Francisco, CA | IP: 198.51.100.42

Post-MPP: What Apple Now Hides or Spoofs

• IP Address: Masked and replaced with Apple relay servers (randomized IPs not linked to users)
• Open Timestamp: Emails are often fetched at random times, not when actually opened
• User Agent Info: doesn’t reflect device or OS accurately
• True Open Event: Can no longer tell if the recipient actually opened the email

Example: ESP logging post-MPP

Opened in Apple Mail | 12:00 AM | Unknown Location | IP: 17.x.x.x (Apple IP)

How Can Marketers Identify MPP Opens?

• Apple IP ranges:
  • Apple preloads emails from known IP addresses (17.0.0.0/8 range).
  • Platforms match these IPs to Apple's public ASN (Autonomous System Number).
• Timing Patterns:
  • MPP opens often happen seconds after delivery, regardless of user behavior
• User Agent Strings:
  • Some platforms analyze headers for common Apple Mail signatures or obfuscation signs.

How Platforms Like HubSpot Detect MPP

Labels opens as "Apple Privacy Open" based on:

• IP match with Apple infrastructure
• Timing anomalies (e.g. instant opens)
• User agent strings