What are the main benefits of excluding unengaged email subscribers?

The primary benefit is improved email deliverability and sender reputation. By excluding unengaged subscribers, you show ISPs that your list is active and interested, which increases your open and click rates, and reduces spam complaints. This signals that your emails are valuable, helping them reach the inbox more reliably.

How do I define an 'unengaged' email subscriber for my business?

It depends on your sending frequency. For daily senders, 30-60 days of no activity might be considered unengaged, while for weekly senders, it could be 90 days. For monthly newsletters, it could extend to 4-6 months. Define what unengaged means for your specific program to set appropriate thresholds.

When is the right time to try re-engaging excluded subscribers?

A re-engagement campaign can be attempted after your sender reputation has improved from excluding unengaged subscribers. The timing should be careful, often after 90 to 180 days of exclusion. It is crucial to manage deliverability during re-engagement to avoid undoing progress.

Should re-engagement campaigns be sent separately from regular emails?

Yes, it is often best to send re-engagement emails to a separate, isolated segment. This minimizes the risk to your main sending reputation if a high percentage of these previously unengaged subscribers continue to ignore your emails or mark them as spam. Once they re-engage, you can move them back to your active list.

What happens if unengaged subscribers don't respond to re-engagement efforts?

If subscribers do not re-engage after your dedicated campaigns, they should be permanently removed from your list, a process known as sunsetting. Continuing to send to them risks damaging your sender reputation further and impacts the overall health of your email program.

How long should I exclude unengaged email subscribers to improve deliverability? - Sender reputation - Email deliverability - Knowledge base

Dealing with unengaged email subscribers is a challenge many marketers face. You might have a large list, but if a significant portion of it hasn't opened or clicked your emails in a long time, it's actually hurting your email deliverability. Internet Service Providers (ISPs) like Klaviyo and Mailgun use engagement metrics as a key factor in deciding whether your emails land in the inbox or the spam folder. When a high percentage of your emails go unread, it signals to ISPs that your content isn't relevant or desired by recipients, which can damage your sender reputation.

Excluding these unengaged subscribers from your regular sends is a crucial step towards improving your deliverability. The main goal is to send emails only to those who actively want to receive them, thereby boosting your open rates, click-through rates, and overall engagement. This positive signal helps rebuild your domain reputation with ISPs. The big question then becomes, how long should you keep them excluded before considering a re-engagement attempt or permanent removal?

The impact of unengaged subscribers on deliverability

A high volume of unengaged subscribers can significantly degrade your email deliverability. When ISPs observe that your emails are consistently ignored, marked as spam, or not opened, they begin to classify your sending domain as less trustworthy. This leads to your messages being routed directly to the spam folder, or in severe cases, your sending IP or domain being placed on a blacklist (or blocklist). The presence of spam traps on your list, which are often old and inactive addresses repurposed by ISPs, can also cause severe damage.

Continuing to send emails to a segment of your audience that shows no interest is a drain on resources and actively undermines your email program. It inflates your sending volume unnecessarily and distorts your engagement metrics, making it harder to accurately assess campaign performance. This cycle perpetuates poor deliverability and makes it difficult for even your most engaged subscribers to receive your content consistently.

The long-term effects of neglecting list hygiene are significant, potentially leading to widespread deliverability issues across your entire sending domain. It is crucial to address this by segmenting or excluding unengaged contacts to prevent further harm to your sender reputation and ensure your legitimate messages reach their intended recipients.

Risks of not excluding unengaged subscribers

Lower inbox placement: ISPs may filter emails to spam or block them entirely due to low engagement.
Reputation damage: Your sender reputation can suffer, affecting all future email campaigns.
Increased spam complaints: Unengaged recipients are more likely to mark your emails as spam.
Higher costs: Many email service providers charge based on list size, meaning you pay for non-performing contacts.
Misleading analytics: Poor engagement rates from inactive users skew your campaign performance data.

Defining inactivity and appropriate exclusion periods

The ideal exclusion period for unengaged subscribers is not a one-size-fits-all answer. It largely depends on your specific sending frequency, the nature of your content, and your industry. For businesses that send emails daily or several times a week, inactivity might be defined as no engagement (opens or clicks) for 30 to 60 days. For those sending weekly or bi-weekly, a 90-day period without engagement might be more appropriate. If you send monthly newsletters, you might extend this to 4-6 months, as suggested by some experts, or even up to 12 months for very infrequent communications.

The key is to define what "unengaged" means for your specific email program and business model. You'll need to monitor your engagement metrics closely and set thresholds that make sense for your audience. Once a subscriber crosses that threshold, they should be moved to an unengaged segment and excluded from your primary mailing list. This immediate action helps stop the bleeding of your sender reputation.

For many, excluding these contacts for a period of 90 to 180 days (3 to 6 months) is a common practice to allow your sender reputation to recover. During this time, ISPs will see higher engagement rates from your active list, gradually improving your standing. It's a proactive step to prevent your emails from consistently landing in the spam folder due to a large percentage of unresponsive recipients. However, always consider your audience's unique behavior.

Sending Frequency	Typical Inactivity Threshold	Suggested Exclusion Period
Daily/Several times a week	30-60 days no opens/clicks	60-90 days
Weekly/Bi-weekly	90 days no opens/clicks	90-180 days
Monthly/Quarterly	4-6 months no opens/clicks	6-12 months

Strategies for re-engagement and managing exclusions

Once you've excluded unengaged subscribers for a sufficient period and seen your deliverability metrics improve, you might consider a re-engagement campaign. This should be a carefully planned series of emails aimed at prompting a response from these dormant contacts. The content must be highly compelling, offering something new, exclusive, or a reminder of the value you provide. It's often a good idea to directly ask if they still want to receive your emails. You can learn more about how to re-engage inactive subscribers for best practices.

However, re-engaging comes with risks. If a large number of these subscribers still don't respond or, worse, mark your re-engagement emails as spam, it can instantly negate the deliverability improvements you've worked hard to achieve. For this reason, it's often recommended to send re-engagement campaigns to a separate, smaller segment of your unengaged list, rather than mixing them with your active recipients. This isolation helps contain any potential negative impact.

After a re-engagement campaign, any subscribers who still do not show signs of activity should be permanently removed from your mailing list. This process is often called "sunsetting" and is a critical part of maintaining email list hygiene. While it might seem counterintuitive to remove contacts, a smaller, highly engaged list is far more valuable for deliverability and overall marketing success than a large list filled with dormant addresses. This ensures your efforts are focused on those most likely to convert and prevents your domain from being flagged as a sender of unwanted mail.

Continuously monitoring engagement is key. If you notice a high percentage of non-opens and non-clicks over time, you may need to adjust your exclusion period or re-engagement strategy. Regularly cleaning your email list is not a one-time task but an ongoing commitment to healthy email deliverability. This systematic approach ensures that you are consistently sending to an audience that values your content, which is the cornerstone of successful email marketing.

Re-engagement strategy risks

Spam complaints: Suddenly emailing very old contacts increases the likelihood of them marking your emails as spam.
Lower engagement rates: Many recipients may still not open or click, pulling down your overall engagement metrics.
Reputation setback: A failed re-engagement campaign can erase recent improvements in sender reputation.
Resource drain: Designing and executing re-engagement campaigns takes time and effort for potentially low returns.

Mitigation tactics

Segment campaigns: Send re-engagement emails only to a separate segment to isolate risk.
Compelling offer: Provide a strong incentive or exclusive content to encourage re-engagement.
Clear opt-in: Make it easy for them to confirm their interest or opt-out.
Sunset non-responders: Permanently remove subscribers who do not re-engage after the campaign.

Monitoring progress and maintaining list health

After excluding your unengaged subscribers, closely monitor your email deliverability metrics. Look for improvements in open rates, click-through rates, and a decrease in spam complaints and unsubscribes. You should also regularly check whether your domain or IP is on any blocklists. Positive trends across these indicators will confirm that your exclusion strategy is working.

Maintaining a healthy email list is an ongoing process. Regularly define and re-evaluate your criteria for identifying unengaged subscribers and integrate list cleaning into your routine email marketing operations. This proactive approach to managing your subscriber list is fundamental for long-term email deliverability success and ensuring your messages consistently reach engaged recipients.

Views from the trenches

Best practices

Always segment re-engagement campaigns to isolate potential negative impacts on your sender reputation.

Make sure your re-engagement emails offer real value, like exclusive content or a special offer, to incentivize opens and clicks.

Clearly ask subscribers if they want to remain on your list; provide an easy opt-in confirmation option.

Define inactivity based on your sending frequency and audience behavior, not a generic timeframe.

Regularly clean your email list. It's an ongoing process, not a one-time fix for deliverability issues.

Common pitfalls

Sending re-engagement emails to unengaged contacts too soon after exclusion, risking spam complaints.

Not providing compelling content in re-engagement emails, leading to continued disinterest.

Ignoring other deliverability factors besides engagement, as exclusion alone may not solve all issues.

Throwing unengaged subscribers back into the general mailing list without explicit re-opt-in, causing high spam spikes.

Failing to remove non-responders after re-engagement attempts, which perpetuates a bloated, low-quality list.

Expert tips

Analyze your campaign data to confirm that your deliverability is consistently improving before re-engaging.

Consider leveraging external data vendors to identify email addresses that are active elsewhere, but still be cautious.

If deliverability is a significant issue, aim for a consistent good reputation for at least 100 days before altering strategy.

Small, random samples of slightly less engaged contacts can be included in regular sends over time to test their responsiveness.

Automate processes to re-engage or put unengaged subscribers on ice based on clear, pre-defined engagement rules.

Marketer view

Marketer from Email Geeks says that sending communications to non-opens after a long break can cause a high spike in spam complaints once they are re-added to the active list, as recipients might not remember signing up.

2021-05-18 - Email Geeks

Marketer view

Marketer from Email Geeks notes that trying to re-engage an unengaged audience typically yields only a 2-3% re-opt-in rate, emphasizing the need for highly compelling content focused on an explicit

2021-05-18 - Email Geeks

Maintaining a healthy email list

The duration for which you should exclude unengaged email subscribers is not fixed, but generally ranges from 60 to 180 days, depending on your email frequency and overall engagement strategy. The primary objective is to signal to ISPs that your list consists of active, interested recipients, thereby improving your sender reputation and reducing the likelihood of your emails going to spam. Remember, a smaller, highly engaged list is far more beneficial for your deliverability than a large list with many inactive contacts.

Effective list hygiene is an ongoing process that involves consistently monitoring engagement, segmenting your audience, and making strategic decisions about re-engagement or permanent removal. By committing to these practices, you can ensure your email program remains healthy, your messages reach the inbox, and your marketing efforts yield the best possible results.