How should I re-engage a dormant email list with high spam complaints?

Key findings

• Complaint Discrepancy: There can be a significant difference between spam complaint rates reported by an Email Service Provider (ESP) and those shown in aggregated reports from a marketing platform, or even Google Postmaster Tools. ESPs often calculate rates per mailbox provider, while marketing platforms may show overall percentages, leading to a misleadingly lower total. This means a 0.14% total could still indicate specific, high complaint rates at certain ISPs.
• Dormancy Risk: Even permissioned lists that have been dormant for several months are prone to higher spam complaints and lower engagement, impacting sender reputation. Recipients may have forgotten their opt-in or lost interest, making unexpected emails unwelcome.
• Audience Context: For tech-savvy audiences using services like identity security, re-engagement can be more successful if the messaging is relevant to their prior engagement (e.g., new feature announcements). Older registrants showing higher click rates indicate potential for selective re-engagement.
• Impact on Reputation: High spam complaints, even if not immediately reflected in Google Postmaster Tools, can negatively affect your domain's sender reputation over time, leading to future deliverability issues and blocklisting. It is crucial to address this proactively to avoid broader problems.

Key considerations

• Segmentation: Before any re-engagement, segment your list based on engagement levels, last open/click date, and user status (e.g., free trial, paid, freemium). This allows for a more targeted approach, focusing on those most likely to re-engage, as discussed in our guide on how to re-engage inactive email subscribers.
• List Validation: While you validated your list, continuous monitoring for invalid addresses is essential. Even a small percentage of dead emails can harm your sender score.
• Gradual Re-engagement: Sending to dormant segments in small, carefully monitored batches is preferable to a large blast. This helps prevent spikes in complaints or bounces, which can lead to your domain or IP being put on a blocklist. Our article on managing deliverability with inactive subscribers provides more detail.
• Content and Frequency: The content of your re-engagement emails should be highly valuable and clearly remind subscribers of their initial relationship with your brand. Consider a series of emails with varying content and clear calls to action, including an easy unsubscribe option.

Key opinions

• Risk of Cold Emailing: Sending to truly cold or unengaged lists that haven't received emails in a long time is highly likely to lead to issues with spam complaints.
• Importance of Context: The success of re-engaging a dormant list depends heavily on how long it has been inactive, the nature of the product or service, and the original reason for subscription. An onboarding sequence followed by a random email months later can be perceived as annoying.
• High Complaint Thresholds: A 0.14% complaint rate, even if it seems low overall, is considered high for a permission-based list, indicating a potential issue with subscriber engagement or list quality.
• Service Suitability for Re-engagement: Some services, especially those related to security and privacy, might be better suited for reviving old lists, particularly if the audience is tech-savvy and previously engaged with the platform.

Key considerations

• Define Churn: Clearly defining what constitutes a dormant or churned subscriber based on your sales cycle and product engagement is vital for strategic re-engagement.
• Strategic Segmentation: Further segmenting dormant lists, perhaps by deferring outreach to less engaged or trial-only users, can mitigate risks. Focus on segments with higher previous engagement.
• Message Relevance: Ensure re-engagement content is highly relevant and provides clear value, such as new feature announcements or benefits that align with their past interactions.
• From Information: Maintaining consistent from email addresses, display names, and branding (logo) helps recipients recognize the sender, potentially reducing complaints.

Key opinions

• Reporting Discrepancies: ESPs like Mailgun often calculate spam complaint rates as a percentage of emails sent to a specific mailbox provider (e.g., Microsoft), while front-end platforms may aggregate complaints as a percentage of total sends. This can make the latter seem deceptively low.
• Thresholds for 'High Percentage': Different platforms and providers have varying internal thresholds for what constitutes a 'high percentage' of spam complaints. What one considers acceptable, another may flag as problematic.
• 0.14% is Concerning: A 0.14% complaint rate is generally higher than expected for a permission-based list, even if it's dormant. This indicates a need for deeper investigation into the list's quality and engagement.
• Challenging but Possible: Reviving an old, dormant list, especially with prior engagement, is one of the most challenging email deliverability puzzles, but it is not impossible with significant effort and a strategic approach.

Key considerations

• Aggressive Cleaning: For deeply dormant lists, aggressively cutting out disengaged segments is often recommended to protect sender reputation. This proactive approach helps avoid further spam complaints and blocklist issues. You can find more information in our article on convincing management to remove inactive subscribers.
• Strategic Batching: If re-engagement is pursued, sending in small, carefully managed batches is crucial to mitigate risk and monitor performance. This is particularly relevant when warming up an old email list.
• Data-Driven Decisions: Rely on metrics beyond total complaints, looking at per-ISP complaint rates and engagement signals to make informed decisions about who to continue emailing. For more insights on this, refer to Word to the Wise's guidance on cleaning old lists.
• Prioritize Deliverability: Ultimately, preserving your sender reputation and deliverability should be the top priority, even if it means sacrificing a portion of your dormant list. A clean, engaged list is more valuable than a large, unengaged one.

Key findings

• Engagement Metrics: Mailbox providers heavily weigh user engagement signals, such as opens, clicks, and replies, as positive indicators, while spam complaints and unsubscribes are negative signals that can trigger filtering.
• Complaint Impact: A spam complaint rate exceeding 0.1% to 0.5% (depending on the ISP) is often considered detrimental to sender reputation and can lead to emails being sent directly to the spam folder or rejected entirely.
• List Quality: Dormant lists are a breeding ground for spam traps and invalid addresses, which, if mailed, can rapidly degrade sender reputation and result in blocklisting.
• Reporting Differences: Many ESPs provide detailed complaint data per Internet Service Provider (ISP), which can reveal targeted issues even if overall complaint rates seem low. This granular data is more indicative of true deliverability health.

Key considerations

• Opt-in Refresh: For very old or dormant lists, consider an explicit re-opt-in campaign. This re-confirms interest and removes disengaged subscribers, albeit potentially shrinking your list significantly. This also helps align with best practices from our email deliverability issues guide.
• Small Batches and Monitoring: When attempting re-engagement, start with the most recently active segment of the dormant list and send in small, controlled batches. Continuously monitor real-time spam complaint rates and adjust sending volume or strategy accordingly. This is a core component of safely messaging inactive email addresses.
• Clear Unsubscribe: Always provide a clear, one-click unsubscribe option. Making it easy for recipients to opt-out reduces the likelihood of them marking your email as spam. This practice is highlighted in re-engagement campaign best practices.
• Sunset Policy: Implement a rigorous sunset policy to automatically remove subscribers who show no engagement after a defined period (e.g., 6-12 months). This prevents future accumulation of dormant addresses and protects your sender reputation.