How do I improve email deliverability for a client with a dormant list and low sending volume?

Key findings

• Dormant list risk: Sending to a list that has been inactive for several months (like since February) carries significant risks, including high spam complaints and bounces, which will further harm sender reputation. Old email blocklists are more likely to pick up domains that send to unengaged recipients.
• Sender reputation: Without proper domain warm-up or consistent sending, a new domain will likely start with a low or non-existent sender reputation, leading to emails landing in spam folders.
• Engagement segmentation: While building engagement-based segments is a good practice, defining 'engaged' for a dormant list with low sending history can be challenging and may not accurately reflect current recipient intent.
• Low volume impact: Very low sending volumes can prevent data from appearing in tools like Google Postmaster Tools, making it harder to diagnose issues and track reputation changes. Standard deliverability fixes often rely on statistical data which is absent in low-volume scenarios.
• Non-opt-in lists: Lists acquired without explicit opt-in (e.g., friends and family) are highly prone to spam complaints and should be treated with extreme caution or removed, as they are likely to negatively impact sender reputation.

Key considerations

• List hygiene: Aggressively cleaning the list with a reliable email verification service (like NeverBounce) is a critical first step to reduce bounces and identify potential spam traps.
• Re-engagement strategy: Consider a specific re-engagement campaign for the dormant, opted-in segments, focusing on value proposition to prompt explicit consent or interaction. This aligns with advice on managing deliverability when re-engaging inactive subscribers.
• Authentication standards: Ensure full compliance with email authentication protocols such as SPF, DKIM, and DMARC, as well as one-click unsubscribe. These are foundational for good deliverability, as detailed in a simple guide to DMARC, SPF, and DKIM.
• Domain reputation building: For a client currently in spam, rebuilding domain reputation is paramount. A step-by-step guide to fixing Gmail delivery can provide a framework for this process.
• Strategic segmentation: Carefully define engagement. For a dormant list, 'clicked 3 times in the past year' might not be sufficient to indicate current interest, especially if that engagement was prior to the dormant period. Focus on the most recent, explicit engagement.

Key opinions

• Coherent strategy: The approach of verifying emails, segmenting by engagement, and gradually increasing sends is generally seen as a sound initial strategy for dormant lists.
• List source matters: The way emails were collected significantly impacts deliverability. Naturally opted-in lists are always preferred, while non-opt-in lists, even of known contacts, can be problematic.
• Engagement definition: There is a need to critically evaluate what constitutes 'engagement' for a long-dormant list, as past clicks or opens might not indicate current interest or a positive signal for email filters.
• Gradual re-engagement: A slow, segmented re-engagement process is favored to allow time for inbox providers to assess the sender's reputation, especially for volumes that are too low to register on tools like Google Postmaster Tools.

Key considerations

• Initial clean-up: Start by removing unengaged subscribers and invalid emails immediately before any sends. This is a core part of improving deliverability with unengaged lists.
• Re-permission campaigns: For deeply dormant or questionable lists, a re-permission campaign asking subscribers if they still wish to receive emails can be more effective than trying to infer engagement. This helps to re-engage stale email subscribers.
• Content relevance: Ensure the content sent to reactivated segments is highly relevant and provides immediate value to encourage opens and clicks, signaling positive engagement to ISPs.
• Monitoring: Even with low volume, closely monitor any available metrics (opens, clicks, unsubscribes, spam complaints within the ESP) to adapt the sending strategy quickly. While Google Postmaster Tools might not show data yet, consistent sending to engaged recipients will eventually provide data points.

Key opinions

• True engagement: Engagement fundamentally means that people desire the emails they receive. Past interactions, especially if old, may not reflect current interest.
• Proactive re-permission: Instead of attempting to resurrect a dormant list based on old data, it is more effective to run a campaign that asks recipients to confirm their desire to receive mail.
• Low volume challenges: Standard deliverability fixes often depend on sufficient sending volume for statistical analysis by machine learning filters. With extremely low volumes (e.g., ~100 messages/day), these methods are less effective.
• Non-target lists: Lists like friends and family who are not primary buyers or targets should be completely excluded from ongoing campaigns to avoid negative feedback signals.

Key considerations

• Define engagement carefully: Recognize that 'clicked 3 times in the past year' may not be a strong enough indicator of current engagement, especially after a prolonged period of inactivity. Focus on recent, explicit actions.
• Rethink dormant segments: If a list has been dormant for many months, assuming continued engagement is risky. Consider a re-permission strategy that explicitly confirms subscriber interest, as discussed in how to re-engage a dormant email list.
• Volume and statistics: Understand that a 10K list, if largely unengaged or dormant, might still yield low *effective* sending volume, hindering the ability of ISPs to accurately assess reputation. This means conventional domain warming might need adjustments for improving email deliverability with domain warm-up.
• Postmaster tools utilization: Even if Google Postmaster Tools currently show no data, it's vital to have it set up. As volume increases and engagement improves, data will become available, providing crucial insights into complaint rates, domain reputation, and delivery errors.

Key findings

• Maintain list health: Keeping an eye on bounce rate, complaint rate, and delivery rate is crucial. Removing inactive or invalid emails is a continuous process recommended by providers like EmailTooltester.
• Sender reputation building: Establishing a strong sender reputation is key to ensuring emails are delivered to the inbox, as highlighted by Klaviyo Help Center. This is especially true for new or inconsistent senders.
• Gradual sending: Avoid sudden spikes in volume. Mailgun and Retainful recommend gradually increasing sending volume for new or re-engaged lists to allow ISPs to recognize the sender as legitimate.
• Consent and opt-in: Salesforce emphasizes obtaining explicit consent from subscribers through transparent opt-in processes to ensure a clean and engaged email list.

Key considerations

• Bounce rate management: Customer.io recommends keeping the overall bounce percentage under 5%, ideally below 2%. High bounce rates, especially hard bounces, signal a poor list and negatively impact reputation. Consistent email deliverability testing can help.
• Inactive subscriber handling: Quora suggests moving inactive subscribers to a stop list and occasionally attempting re-engagement. If re-engagement fails, removal is often necessary to protect sender reputation.
• Authentication compliance: Properly authenticating emails with SPF, DKIM, and DMARC is a fundamental requirement for optimal deliverability. Without these, even good content and a clean list may end up in spam. This impacts overall email and domain reputation.
• Content and frequency: Onesignal highlights that content structure and consistent message frequency are important factors. Avoiding spam triggers in content and sticking to a consistent sending schedule builds trust with ISPs.