Open rate segmentation is the practice of categorizing email subscribers into distinct groups based on how frequently they open your emails. This segmentation strategy enables marketers to tailor their messaging, frequency, and re-engagement tactics to match subscriber engagement levels, ultimately improving deliverability and campaign performance.
Creating Engagement-Based Segments
Email lists are typically divided into three primary engagement tiers. Frequent openers are highly engaged subscribers who consistently open emails, often defined as those who have opened at least one email in the past 30 days. Occasional openers show moderate engagement, typically opening emails sporadically over a 30-90 day period. Never or rarely openers represent inactive subscribers who haven’t engaged with emails for 90+ days or have never opened any campaigns.
The specific timeframes for these segments should be adjusted based on your sending frequency and industry benchmarks. A daily newsletter might consider someone inactive after 60 days, while a monthly publication might extend this to 6 months.
Strategies for Each Segment
Each engagement tier requires a distinct approach. For frequent openers, maintain regular communication with your best content, offer exclusive perks or early access, and gradually increase sending frequency while monitoring engagement. These subscribers are your advocates and should receive premium treatment.
Occasional openers benefit from reduced sending frequency to avoid overwhelming them, A/B testing different subject lines and send times to optimize engagement, and more targeted content based on previous interaction patterns. The goal is to convert them into frequent openers through relevance.
Never openers require careful handling through re-engagement campaigns before considering removal, significantly reduced email frequency to preserve sender reputation, and sunset policies to eventually remove consistently unengaged subscribers for better list hygiene.
Re-engagement and List Hygiene
Re-engagement campaigns serve as a final attempt to revive inactive subscribers. These campaigns should feature compelling subject lines asking “Are you still interested?”, offer incentives like exclusive discounts or content, provide preference center access to update communication preferences, and include a clear unsubscribe option to maintain list quality.
From a list hygiene perspective, regularly removing never openers improves deliverability by maintaining positive engagement metrics that ISPs monitor, reduces sending costs by eliminating inactive addresses, and provides more accurate performance data for strategic decisions.
Privacy Limitations and Modern Challenges
Apple’s Mail Privacy Protection (MPP), introduced in 2021, has significantly impacted open rate segmentation. MPP pre-loads email content and images for Apple Mail users, registering false opens regardless of whether recipients actually view the email. This affects approximately 40-50% of email users and makes traditional open rate segmentation less reliable.
Modern best practices now incorporate additional engagement signals beyond opens, including click-through rates as a more reliable engagement indicator, conversion data and revenue attribution, reply rates and direct engagement, and time-based engagement patterns. Combining multiple metrics creates more accurate segmentation models in the privacy-conscious email landscape.
Effective open rate segmentation requires balancing data-driven insights with privacy considerations, continuously adapting strategies as engagement patterns and technology evolve.