How long should I keep inactive email addresses on my marketing list?
Michael Ko
Co-founder & CEO, Suped
Published 2 Aug 2025
Updated 17 Aug 2025
7 min read
One of the most common questions I hear from marketers is about managing inactive email addresses. It's not a straightforward answer, as there's no universal magic number for how long you should keep these contacts on your list. The optimal duration varies significantly based on several factors unique to each sender and their audience.
Maintaining a clean and engaged email list is crucial for achieving good email deliverability and protecting your sender reputation. Sending emails to subscribers who no longer open or click can harm your overall email program, leading to lower inbox placement rates and higher costs.
In this guide, I'll walk through the considerations, risks, and strategies to help you decide how long to keep inactive email addresses, and what to do with them once you've made that decision.
Understanding inactivity and its impact
An inactive email address typically refers to a subscriber who has not opened, clicked, or otherwise engaged with your emails over a specific period. This period can range from 90 days to 12 months or even longer, depending on your email frequency and the nature of your content. Knowing what constitutes an inactive user for your specific sending patterns is the first step in effective list management.
Sending to unengaged subscribers can significantly impact your deliverability. When internet service providers (ISPs) see low engagement rates or a high number of messages sent to addresses that don't interact, they may start to flag your emails as unwanted, pushing them to the spam folder or even blocking them. This is especially true for free email providers. You can learn more about the pitfalls of inactive contacts.
The risks of maintaining a large segment of inactive contacts extend beyond deliverability. They include increased costs from your email service provider (as many charge by list size), inaccurate analytics that misrepresent your true engagement, and the potential to hit spam traps. Understanding the risk of sending email to inactive users highlights why regular list hygiene is essential.
The drawbacks of keeping inactives
Damaged sender reputation: ISPs interpret sending to unengaged users as a sign of low-quality content or even spamming, leading to lower inbox placement rates.
Increased costs: Many email service providers (ESPs) charge based on list size, meaning you pay for contacts who aren't contributing to your marketing goals.
Higher bounce rates: Inactive addresses can turn into hard bounces over time, signaling a poorly maintained list.
Spam trap risks: Old or abandoned email addresses can be converted into spam traps. Sending to these can severely damage your sender reputation and lead to blacklisting.
The benefits of purging inactives
Improved deliverability: Focus your sending on engaged subscribers, signaling to ISPs that your content is valued.
Cost savings: Reduce your ESP fees by only paying for active, valuable contacts.
Accurate analytics: Get a clearer picture of your campaign performance with metrics based on genuinely interested recipients.
Reduced spam complaints: Less chance of recipients marking your emails as spam if they are actively engaging with your content.
Key factors in determining inactivity duration
The definition of an 'inactive' subscriber is highly contextual. For a daily news brief, 30 days of no engagement might signal inactivity. For an annual conference announcement, 11 months of silence could still be considered normal. Consider your typical sales cycle, the nature of your content, and how frequently you communicate. A B2B cycle for a high-value product, for instance, might naturally have longer periods of inactivity between engagements compared to a daily e-commerce promotion.
The type of emails you send also plays a significant role. Transactional emails, like order confirmations or shipping updates, are expected to have high open rates and are less about ongoing engagement. Marketing emails and newsletters, however, rely on sustained interaction. If you're sending promotional material, a shorter inactivity window before considering a purge might be appropriate. Some newsletters, especially those with archival value, might never fully purge their lists.
ISPs (Internet Service Providers) like Google and Microsoft are increasingly strict about sender reputation and list hygiene. Google, for instance, has policies that lead to account deactivation after prolonged inactivity. While Yahoo and Microsoft typically bounce emails to truly inactive accounts, Google might let them sit and accept mail, turning them into spam traps over time. This makes active list management even more critical.
A common rule of thumb from ISPs is to consider emails inactive if there's no engagement within six months, though this can vary from three to nine months based on specific business needs and sending volume. For example, a Word to the Wise article suggests 12-24 months for purging to prevent spam traps, depending on how often you send emails. If you send frequently, a shorter window (like 90 days) is often recommended. If your emails are sent less often, a longer period up to 24 months might be acceptable, particularly if you're not experiencing deliverability issues.
Factor
Recommended Inactivity Threshold
High frequency marketing (daily/weekly)
90-180 days (3-6 months)
Low frequency marketing (monthly/quarterly)
180-365 days (6-12 months)
Newsletter (non-promotional)
1-2 years (or longer with re-engagement)
Association/membership based
Up to 2 years, especially if paid membership
Strategies for managing inactive subscribers
Before you remove inactive addresses, it's often a good practice to try to re-engage inactive email subscribers. A targeted re-engagement campaign can help identify subscribers who still want to hear from you but might have simply overlooked previous emails. This usually involves a series of emails with compelling offers, asking them to update preferences, or explicitly confirm their interest. If they respond, great; if not, then it's a clear signal to move forward with list hygiene.
After a re-engagement effort, segment your list. Move unengaged subscribers to a separate list or suppress them from regular mailings. This allows you to maintain a core active list for your main campaigns, while potentially retaining the unengaged segment for very infrequent, highly targeted messages (e.g., annual updates or major promotions). Implement a sunsetting policy for inactive subscribers which clearly defines when contacts are moved or removed.
Ultimately, if subscribers remain inactive after re-engagement attempts and pass your defined inactivity threshold, removing or suppressing them from your active mailing list is beneficial. This helps maintain a healthy email list, improves your deliverability metrics, and ensures your campaigns reach the audience most likely to engage.
Best practices for list hygiene
Regularly monitor engagement: Track opens, clicks, and conversions to identify inactive subscribers promptly.
Segment your audience: Create segments for active, inactive, and highly engaged users.
Implement a re-engagement strategy: Before removing, try to win back inactive subscribers with targeted campaigns.
Set clear sunsetting policies: Define when and how inactive subscribers are suppressed or removed from your list.
Regularly remove hard bounces: Addresses that consistently hard bounce should be removed immediately to protect your sender reputation.
Views from the trenches
Best practices
Actively manage your email lists, especially considering your specific industry and content type.
Segment your list into active and inactive subscribers, then run re-engagement campaigns.
Remove hard bounces immediately as they significantly harm your sender reputation.
Understand that ISP policies vary; some bounce inactives, others turn them into spam traps.
Adjust your inactivity threshold based on your email frequency and purchase cycle.
Common pitfalls
Keeping inactive email addresses on your primary mailing list for too long.
Ignoring low engagement rates, which can lead to negative sender reputation.
Not implementing a re-engagement strategy before outright purging subscribers.
Failing to adapt your list hygiene practices to different industries or content types.
Overlooking the financial cost of sending emails to unengaged contacts.
Expert tips
For marketing emails, a 90-day to 1-year inactivity window is a common guideline.
Newsletters can sometimes retain inactive subscribers for longer, up to 2 years, if there are no deliverability issues.
Consider whether email addresses are free (Gmail, Yahoo) or paid (broadband, corporate), as this can impact their longevity.
Be aware of how ISPs like Google manage abandoned accounts, as they can become spam traps.
Always prioritize maintaining a clean list over simply having a large list size.
Marketer view
Marketer from Email Geeks says that engagement policies are highly dependent on the vertical or industry, noting that the events industry has different needs than e-commerce.
2024-06-27 - Email Geeks
Expert view
Expert from Email Geeks says that while it varies, a general range for inactive email addresses is between 90 days and 2 years, influenced by the purchase cycle and any existing deliverability problems.
2024-06-27 - Email Geeks
Conclusion
There's no single answer to how long to keep inactive email addresses on your marketing list. It truly depends on your specific industry, email frequency, the type of content you send, and your overall email marketing goals. However, a proactive approach to list hygiene is universally beneficial.
Regularly monitoring engagement metrics, implementing re-engagement campaigns, and defining clear sunsetting policies are key steps. These practices not only save you money but also significantly improve your email deliverability, ensuring your messages reach the inbox of those who genuinely want to receive them. Learn more about why your emails might be failing.
By focusing on quality over quantity and maintaining a healthy, engaged list, you can build a stronger sender reputation and maximize the effectiveness of your email marketing efforts. Your proactive approach to managing inactive (or unengaged) subscribers will yield long-term positive results for your email program.
Google and 
Microsoft are increasingly strict about sender reputation and list hygiene. Google, for instance, has policies that lead to account deactivation after prolonged inactivity. While Yahoo and Microsoft typically bounce emails to truly inactive accounts, Google might let them sit and accept mail, turning them into spam traps over time. This makes active list management even more critical.
