Increased Email Security Measures: To protect users from phishing and spam, security software and spam filters have become more sophisticated. These solutions often scan incoming emails and automatically "open" them to detect malicious content before the recipient even sees the email. While this protects users, it creates false positives in open rates since the email is being opened by a bot, not a human.

Apple’s Mail Privacy Protection (MPP): Introduced by Apple, MPP hides recipients’ email activity from senders by preloading email content (including tracking pixels) before the user actually opens the email. This means that any email sent to Apple users is recorded as opened even if the recipient never actually views it, inflating open rates and distorting the data.

Spam Filter and Bot Activity: Many email clients and servers use bots to pre-check emails to determine if they are safe for the recipient. This is especially true for business and corporate email domains, where strict security settings are in place. These bots open emails and click links to scan for threats, further contributing to false open rates.

Evolving Email Marketing Practices: As email marketing becomes more prevalent, ESPs and security providers are constantly developing new ways to detect and block potentially harmful content. This evolving landscape means that automated processes will sometimes inadvertently "open" legitimate marketing emails as part of security checks, falsely increasing open rates.

Accuracy in Performance Metrics: Open rates have traditionally been a key performance indicator (KPI) for email campaigns, helping marketers understand engagement levels. However, with these false opens becoming more common, ESPs are working to develop tools to filter out non-human opens to provide more accurate metrics. This effort is crucial for maintaining reliable data that marketers can trust to make informed decisions on content effectiveness, timing, and audience segmentation.