How should I define unengaged subscribers for removal from my email list?

Key findings

• Variable timeframe: There is no universal standard for how long a subscriber must be inactive to be considered unengaged; durations typically range from 3 months to 18 months, depending on the business context.
• Beyond opens and clicks: Engagement should not be solely defined by email opens and clicks. Other metrics such as website logins, purchases, or interactions with other brand channels should also be considered to get a complete picture of subscriber activity.
• Deliverability impact: Keeping a large segment of unengaged subscribers can negatively impact your sender reputation, leading to lower inbox placement and an increased risk of being added to a blocklist.
• Segment before removal: Before outright removal, it is often beneficial to segment unengaged subscribers and attempt re-engagement campaigns to try and rekindle their interest. See our guide on how to re-engage inactive email subscribers.

Key considerations

• Define your specific criteria: Establish a clear definition of unengagement for your business, considering typical customer lifecycles, purchase patterns, and content relevance. This often involves looking at your own historical data.
• Monitor engagement metrics: Regularly monitor metrics like open rates, click-through rates, and conversion rates, alongside broader customer interactions, to identify declining interest. Campaign Monitor suggests that keeping unengaged subscribers can make it hard to assess true audience engagement.
• Implement re-engagement strategies: Before removing subscribers, try targeted re-engagement campaigns. This can include sending personalized content, special offers, or preference updates.
• Automate suppression: Consider automating the process of suppressing or removing contacts who consistently fail to engage after re-engagement attempts to maintain list hygiene.

Key opinions

• Variable timeframes: Many marketers use a range of 6 months to 18 months of inactivity as a threshold, with some adapting this based on content type, such as fundraising emails.
• Context is key: The definition of unengaged depends on the target group, sending frequency, and the product or service being sold. A business with a long sales cycle might have a longer unengagement window than one with frequent transactions.
• Holistic engagement: Some marketers emphasize looking beyond just email metrics to include other forms of engagement, such as website logins or purchase history, to define a truly unengaged subscriber.
• Impact on analytics: Keeping unengaged contacts on a list can significantly skew email marketing analytics, making it difficult to accurately assess campaign performance and ROI.

Key considerations

• Segment inactive users: Marketers frequently recommend segmenting unengaged contacts into a separate list before deciding on removal, allowing for targeted re-engagement efforts. Klaviyo suggests creating a segment of profiles receiving emails but not opening or clicking.
• Prevent spam complaints: Unengaged subscribers are more prone to marking emails as spam, which can harm sender reputation and lead to blocklisting. This is a primary driver for list cleaning.
• Cost efficiency: Removing inactive subscribers can reduce costs associated with email service providers (ESPs) that charge based on list size, optimizing budget allocation.
• Improve deliverability rates: A clean, engaged list signals to internet service providers (ISPs) that your emails are valued, thereby improving overall deliverability and inbox placement. Read more about how managing inactive email subscribers can improve Gmail deliverability.

Key opinions

• No universal rule: Experts universally agree there is no single, fixed rule for defining unengaged subscribers. The criteria must be specific to the sender's business, sales cycle, and content.
• Reputation impact: Non-interacting subscribers, particularly at major webmail providers like Gmail, can significantly damage overall sender reputation and negatively affect deliverability if kept on the list for too long.
• Distinguishing disinterest vs. spam folder: Senders cannot easily distinguish if a lack of interaction means a subscriber is uninterested or if emails are landing in the spam folder. Therefore, proactive removal is crucial before large numbers of inactive users hurt delivery.
• Beyond email metrics: Engagement should encompass broader customer activity, such as website logins, purchases, or interactions outside of email, to accurately assess a subscriber's value and active status.

Key considerations

• Data-driven decisions: Experts advise analyzing internal data to see if inactive subscribers ever re-engage or make purchases after a long period. This helps quantify their value and inform removal decisions.
• Business-specific approach: The choice of when to remove unengaged subscribers should be based on your specific customer base, their typical interaction patterns, and your business's sales cycle.
• Proactive list management: Regularly cleaning your list prevents accumulation of unengaged contacts that could trigger spam filters or lead to blocklisting (or blacklisting). Our guide on how email blacklists actually work delves deeper into this.
• Observe deliverability trends: Some experts report seeing a dip in deliverability after as little as three months of non-engagement, suggesting that even shorter cycles might be appropriate for some senders. This aligns with advice found on Kickbox Blog, which cites industry best practices to remove unengaged users.

Key findings

• Engagement signals: Documentation implicitly defines engagement through positive signals like opens, clicks, replies, and marking emails as "not spam." A lack of these signals, over time, indicates unengagement.
• Negative signals: Conversely, documentation highlights negative signals such as spam complaints, high bounce rates, and unsubscribes (without prior interaction) as indicators of disengagement and potential list quality issues.
• Sender reputation: Maintaining a high volume of unengaged subscribers can dilute positive engagement signals and increase negative ones, thereby harming sender reputation. Services like Google Postmaster Tools directly reflect this.
• List hygiene importance: Regular list cleaning, which includes removing or suppressing unengaged contacts, is consistently recommended as a best practice for improving deliverability and avoiding blocklists.

Key considerations

• Focus on active users: ISPs and email platforms prioritize delivering emails from senders with strong positive engagement. Focusing on actively engaged users is more effective than attempting to force engagement from disengaged ones.
• Prevent spam traps: Inactive email addresses, if not removed, can eventually turn into spam traps. Sending to these traps can severely damage sender reputation and lead to blacklisting.
• Compliance with sender requirements: Many recent updates from major providers like Gmail and Yahoo emphasize sending only wanted mail. While not explicitly defining unengagement, these requirements implicitly demand that senders maintain lists of recipients who genuinely desire their emails. Mailchimp help documentation provides guidance on identifying and managing inactive subscribers.