How to re-engage inactive email subscribers and when should you stop sending?
Michael Ko
Co-founder & CEO, Suped
Published 5 Jun 2025
Updated 19 Aug 2025
7 min read
Maintaining a healthy email list is crucial for successful email marketing and ensuring strong deliverability. Over time, however, subscribers can become inactive, leading to diminished engagement rates and potential issues with your sender reputation. It's a common challenge to decide whether to try to win back these subscribers or to remove them from your list entirely.
Ignoring inactive subscribers can seriously harm your email program. Internet Service Providers (ISPs) like Gmail and Outlook closely monitor engagement. Low open and click rates, coupled with high spam complaints or unsubscribe rates from inactive users, can signal to ISPs that your emails are not valuable, increasing the likelihood of your messages landing in the spam folder or even being blocked.
This guide explores effective strategies for re-engaging those dormant subscribers and, equally important, helps you determine the critical point at which it's best to stop sending to them. Striking this balance is key to maintaining a strong sender reputation and ensuring your emails reach the right inboxes.
Defining inactive subscribers
Before you can re-engage or remove inactive subscribers, you first need to clearly define what 'inactive' means for your specific email program. This definition can vary depending on your industry, email frequency, and business goals.
Common indicators of inactivity include a lack of opens, clicks, or conversions (like purchases or sign-ups) over a specified period. For some, a subscriber might be considered inactive after 30-60 days of no engagement, while for others, it might be 90 days, six months, or even a year. The optimal timeframe often depends on your typical sales cycle and how frequently you send emails. For example, a daily newsletter would have a shorter inactivity threshold than a monthly product update.
Once you have a clear definition, the next step is to segment these inactive subscribers from your active list. This allows you to target them with specific re-engagement campaigns without negatively impacting your primary sending reputation. This separation is a crucial aspect of balancing engagement between active and inactive email audience segments.
Strategies for re-engagement campaigns
Re-engagement campaigns are specifically designed to rekindle interest from inactive subscribers. The goal isn't to convert every single one but to identify those who still want to hear from you. A re-engagement email is a communication created for the sole purpose of reactivating readers who have stopped engaging with your emails.
Successful re-engagement often involves a series of emails, typically two to three, sent over a short period. Here are some strategies you can implement:
Offer value: Provide a special discount, exclusive content, or early access to a new product/service. Make them feel like they're missing out.
Ask for preferences: Give them the option to update their email frequency or content interests. This empowers them and shows you care about their inbox.
Seek feedback: Send a short survey to understand why they became inactive and what content they would find valuable.
Remind them of benefits: Highlight the core value proposition of your emails or brand. What did they sign up for in the first place?
Crafting compelling subject lines is crucial for cutting through inbox clutter. Here are a few examples that often perform well in re-engagement campaigns:
Re-engagement subject lines
1. We miss you! Here's X% off your next purchase.
2. Don't want our emails anymore? Update your preferences here.
3. Is this goodbye? Keep getting our updates!
4. We've got something special just for you!
When to stop sending emails
Even with the best re-engagement strategies, some subscribers will simply not respond. This is where a sunset policy becomes essential. Continuing to send emails to truly inactive users is detrimental to your deliverability and overall email marketing success.
So, when should you stop sending? The exact timing depends on your re-engagement campaign's results. If a subscriber goes through your entire re-engagement sequence without any signs of interaction (no opens, clicks, or conversions), it's generally time to remove them. Many experts suggest a timeframe of 6-12 months of complete inactivity, after re-engagement efforts, as a common benchmark before suppression. For example, some businesses choose to stop sending to customers who have not made a purchase for more than 12 months.
The primary reasons to remove unengaged subscribers are to protect your sender reputation, avoid spam traps, and improve your overall email metrics. Removing those who no longer want your emails will lead to higher open rates, click-through rates, and lower complaint rates for your active segments. This signals to ISPs that your content is valuable and relevant. For more on this, consider when to remove unengaged subscribers from email lists.
Sending to all inactive subscribers
Costs: Increased email service provider costs due to larger list sizes.
Deliverability: Lower open and click rates, higher bounce rates, and increased spam complaints.
Reputation: Signals to ISPs that your content is irrelevant, risking being placed on blocklists (blacklists) and impacting inbox placement for all subscribers.
Implementing a sunset policy
Costs: Reduced email service provider costs with a leaner, more engaged list.
Deliverability: Improved overall engagement metrics, leading to better inbox placement.
Reputation: Protects sender reputation by removing unengaged users, reducing the risk of spam traps and blocklistings.
Impact on deliverability and sender reputation
Your sender reputation is a critical factor in email deliverability. Every email you send, and how recipients interact with it, influences this reputation. Inactive subscribers, if not managed, can quickly erode this standing.
ISPs track various engagement signals to determine your reputation. When emails are consistently ignored, marked as spam, or bounced due to old addresses, it negatively impacts your sender score. This can lead to your emails being filtered to the spam folder, or worse, your domain or IP address being added to a public or private blocklist (also called blacklist).
Furthermore, old and unengaged lists are breeding grounds for spam traps. Sending to these addresses can immediately flag you as a spammer, leading to severe deliverability issues. This is a common reason why your emails are going to spam. Regular list hygiene, including the removal of unengaged subscribers after a sunset period, is fundamental for maintaining a healthy and high-performing email program. You can also monitor this with a blocklist checker.
A good sender reputation means your emails are more likely to reach the inbox, while a poor one can result in significant deliverability challenges. It's a key component of how to improve your domain reputation.
Views from the trenches
Best practices
Always segment inactive subscribers before initiating a re-engagement campaign to avoid harming your main list's deliverability.
Offer clear incentives or value in your re-engagement emails, such as exclusive content or special discounts.
Provide options for subscribers to update their preferences, allowing them to control content and frequency.
Implement a strict sunset policy to remove subscribers who do not re-engage after multiple attempts and a defined period.
Regularly monitor your email engagement metrics, including opens, clicks, and complaint rates, to identify inactivity trends early.
Common pitfalls
Continuing to send emails to a highly inactive segment, significantly dragging down overall engagement rates and sender reputation.
Sending a single 'win-back' email without a clear call to action or a follow-up strategy.
Not clearly defining what constitutes an 'inactive' subscriber for your specific business model and email frequency.
Failing to remove hard bounces and undeliverable addresses, which signals poor list quality to ISPs.
Using deceptive subject lines or tactics in re-engagement campaigns that might lead to higher spam complaints.
Expert tips
Consider a re-engagement campaign every 3-12 months, depending on subscriber acquisition and business goals.
A re-engagement campaign should be short, typically 2-3 emails sent over one to two weeks, with a clear endpoint.
If a subscriber has no purchase activity for over 12 months, it may be time to stop sending them marketing emails.
Watch for significant drops in response rates and deliverability, as this indicates you've reached the point to stop sending.
When removing inactive users, prioritize those who have never engaged or have been inactive for the longest periods.
Marketer view
Marketer from Email Geeks says to make sure you're sending emails at the right times to re-engage inactive subscribers.
2022-10-21 - Email Geeks
Marketer view
Marketer from Email Geeks says to consider several factors when defining a strategy to re-engage your subscribers who are indeed re-engageable.
2023-07-27 - Email Geeks
Maintaining a healthy email list
Re-engaging inactive email subscribers is a vital component of a healthy email marketing strategy. It's about giving valuable subscribers a chance to reconnect, while also proactively managing your list to protect your sender reputation.
By understanding when a subscriber is truly inactive, crafting compelling re-engagement campaigns, and knowing when to implement a sunset policy, you can significantly improve your email deliverability. This balanced approach ensures your messages consistently reach interested recipients, leading to better engagement and long-term success.
Focus on quality over quantity. A smaller, highly engaged list will always outperform a large list riddled with inactive or unengaged contacts. This strategic management is key to thriving in the complex world of email deliverability.
Gmail and 
Outlook closely monitor engagement. Low open and click rates, coupled with high spam complaints or unsubscribe rates from inactive users, can signal to ISPs that your emails are not valuable, increasing the likelihood of your messages landing in the spam folder or even being blocked.
