Email marketing best practices for unengaged subscribers: opt-out, suppression, or re-engagement?

Key findings

1. Strategic re-engagement: Implementing re-engagement campaigns is a common and effective first step before considering harsher actions like suppression or opt-out. These campaigns aim to identify subscribers who might still be interested, but require a tailored approach.
2. Engagement thresholds: The definition of 'unengaged' (e.g., 6, 9, or 18 months without opens/clicks) varies significantly by company and industry, requiring internal testing and analysis to determine an optimal timeframe that balances revenue and deliverability.
3. Opt-out vs. suppress: A key decision point is whether to permanently opt out inactive subscribers (requiring a full re-opt-in) or merely suppress them, allowing for potential re-activation based on future behaviors (like purchases or transactional email engagement).
4. Deliverability impact: Sending to unengaged subscribers can negatively affect your sender reputation, increasing spam complaints and potentially leading to blocklisting, even if your overall deliverability seems stable.
5. Compliance and data hygiene: Legal and ethical considerations, such as GDPR in Europe, may mandate the deletion of personal data for unengaged contacts after a certain period, impacting how long you can maintain suppressed lists.

Key considerations

1. Define 'unengaged': Clearly establish internal metrics for inactivity (e.g., no opens or clicks for X months) to segment your audience accurately. This will help you know when to remove unengaged subscribers.
2. Re-engagement strategy: Develop a multi-step re-engagement campaign (e.g., 3 emails over a month) that explicitly asks subscribers if they wish to continue receiving communications. This directly addresses engagement, as outlined by Mailgun.
3. Clear re-opt-in paths: If you opt out subscribers, ensure a clear and simple process for them to re-opt-in if their interest is rekindled, such as through a purchase or direct sign-up.
4. Stakeholder alignment: Educate internal stakeholders (e.g., sales, marketing leadership) on the long-term deliverability benefits of list hygiene, even if it means reducing list size. This can help persuade management to support such initiatives.
5. Monitor deliverability: Continuously monitor your inbox placement and sender reputation metrics before and after implementing changes to your unengaged subscriber strategy to assess their impact.

Key opinions

1. Standard practice: Many marketers view a multi-step re-engagement campaign, followed by an opt-out for non-responders, as the correct and responsible approach.
2. Revenue vs. deliverability: There's often a push-and-pull between marketing teams focused on list size (and perceived revenue potential) and deliverability teams prioritizing inbox placement. Data analysis showing no revenue loss from removing inactive subscribers can help resolve this.
3. Defining re-engagement signals: Marketers grapple with whether transactional engagements (like opening a shipping confirmation or making a purchase) should automatically re-subscribe someone to marketing emails after they've been deemed unengaged.
4. Segmentation importance: Segmenting unengaged subscribers, potentially by purchase history or type of inactivity, allows for more targeted re-engagement strategies or removal decisions, as noted by Klaviyo Help Center.

Key considerations

1. Customizable inactivity thresholds: The appropriate time frame for 'unengaged' (e.g., 9 months for e-commerce) should be determined by your business cycle and data, not a generic rule. This is critical for improving Gmail deliverability.
2. Phased re-engagement: If a user shows minimal engagement (e.g., opening a re-engagement email), consider placing them into a low-frequency segment rather than immediately returning them to full email throttle. This falls under managing deliverability during re-engagement.
3. Explicit re-opt-in: For long-term unengaged subscribers, a direct re-opt-in action is generally preferred over assuming interest from transactional activity, as highlighted by Emercury.
4. Communicate value proposition: Re-engagement campaigns should remind subscribers of the benefits they receive, encouraging them to actively choose to continue.

Key opinions

1. Contextual approach: Best practices for managing subscriptions are highly individualized, meaning what works for one company (e.g., 9 months for an e-commerce brand) might not be suitable for another.
2. Bounce handling: If a sender implements robust bounce handling, some experts suggest that the downside of mailing inactive subscribers indefinitely might be minimal, though engagement remains key for inboxing.
3. Proactive re-opt-in: Even if an unengaged subscriber makes a new purchase, the ideal approach is to prompt them for a fresh opt-in for marketing emails, rather than automatically re-subscribing them.
4. Positive user experience: Messaging that acknowledges a previous opt-out while inviting reactivation can create a better user experience and improve the chances of re-engagement.
5. Societal impact: Experts believe that widespread adoption of thoughtful re-engagement and list hygiene practices would significantly improve the overall email ecosystem.

Key considerations

1. Dynamic inactivity definitions: Adapt your definition of 'unengaged' based on your specific business model and email cadence, as 9 months may not be universally applicable for everyone, but it can be beneficial for re-engaging inactive subscribers.
2. Deliverability as a priority: Recognize that continually sending to genuinely unengaged users can negatively impact your sender reputation and lead to issues like blocklisting or increased spam folder placement. This is a common theme from deliverability experts like Spamresource.
3. Purchase-triggered re-opt-in: If a user makes a purchase after being opted out, consider presenting a clear, easy option to re-subscribe to marketing emails during the checkout flow or in a follow-up transactional email. This balances customer experience and compliance.
4. Avoid repeated re-engagement attempts: While re-engagement campaigns are good, repeatedly attempting to engage truly disengaged subscribers can lead to complaints and poor sender reputation. Understand why you might get repeated emails after unsubscribing and avoid it.

Key findings

1. Consent is paramount: Legal frameworks like CAN-SPAM and GDPR underscore the need for explicit consent and easy opt-out mechanisms, making clear re-opt-in processes crucial for previously unengaged contacts.
2. Reputation management: Major mailbox providers (e.g., Google, Microsoft) use engagement metrics as a significant factor in sender reputation. Low engagement from parts of your list can drag down your overall sender score.
3. Data retention policies: Many data privacy regulations encourage or mandate the deletion of personal data when it is no longer necessary for the purpose it was collected, which can apply to long-term unengaged email addresses.
4. Avoiding spam traps: Sending to dormant or old email addresses increases the risk of hitting spam traps, which are a major factor in blocklisting and reputation damage.

Key considerations

1. Implement clear opt-out processes: Ensure your unsubscribe process is straightforward and honored promptly, aligning with industry best practices and legal requirements like CAN-SPAM.
2. Monitor engagement metrics closely: Utilize tools like Google Postmaster Tools to track spam rates and engagement, allowing you to identify segments impacting your sender reputation negatively. This helps in understanding why emails go to spam.
3. Adhere to data privacy regulations: Be aware of regional privacy laws (e.g., GDPR in Europe) that may dictate how long you can retain and process personal data, including email addresses, especially if there's no ongoing engagement. Iubenda provides guidance on re-engagement within these contexts.
4. Regular list hygiene: Regularly clean your email lists by removing hard bounces, spam complaints, and perpetually unengaged subscribers to prevent negative impacts on your sender reputation and avoid landing on a blocklist (or blacklist).