How long should users be inactive before deleting them from my ESP?
Matthew Whittaker
Co-founder & CTO, Suped
Published 29 Jul 2025
Updated 19 Aug 2025
6 min read
Deciding when to delete inactive users from your Email Service Provider (ESP) is a crucial decision for maintaining good sender reputation and optimizing costs. It is common for management to hesitate, fearing loss of potential future engagement, but retaining excessively old or unengaged contacts can lead to significant deliverability issues.
My experience suggests that keeping inactive users for extended periods can result in higher bounce rates, increased spam complaints, and eventually, blocklisting (or blacklisting). These outcomes severely impact your ability to reach active subscribers, making the argument for regular list hygiene compelling.
Why deleting inactive users matters
Retention of inactive users poses several risks that can undermine your entire email program. Email providers, such as Google, actively monitor sending behavior and recipient engagement to determine your sender reputation. A low engagement rate due to a large segment of inactive users can signal to ISPs (Internet Service Providers) that your emails are not valuable, leading them to route your messages to the spam folder or reject them outright.
Another major concern is the presence of spam traps. These are old email addresses repurposed by ISPs to catch senders with poor list hygiene. Hitting a spam trap can immediately land you on a blocklist (or blacklist), severely damaging your deliverability for all future campaigns. The risk of sending email to inactive users includes not just spam traps but also increased complaints, hard bounces, and financial waste.
From a financial perspective, maintaining a large list of inactive users in your ESP means you are paying for contacts that provide no return on investment. Many ESPs charge based on list size or email volume, so a bloated list directly translates to unnecessary expenses. This cost can quickly add up, especially for larger organizations.
Furthermore, a clean email list enables more accurate segmentation and personalization, leading to better campaign performance with active subscribers. Focusing your efforts and resources on engaged users will yield higher open rates, click-through rates, and conversions. It also helps in complying with data privacy regulations like GDPR, which emphasize data minimization.
Defining inactivity and setting a policy
The definition of inactivity is not one-size-fits-all, as it largely depends on your specific business model and typical customer lifecycle. For a SaaS tool with free users, an inactivity period of 90 days or 6 months might be considered long, especially if many users only engaged once and then churned. In contrast, an accounting practice might consider a client inactive only after several years.
I suggest starting by analyzing your own engagement data to define unengaged subscribers for removal. Consider various engagement metrics such as email opens, clicks, website visits, product logins, and purchases. For example, some companies set their inactivity threshold at 12 months for email engagement, while others may look at product usage over a shorter period.
Many providers, like Dropbox, have policies for deleting inactive accounts, often after 90 days of inactivity. Larger email providers, as highlighted in a blog post by Ongage, might allow one to two years before considering deletion, especially for free services. These examples illustrate the variance, but all point to the eventual removal of dormant accounts.
The process of sunsetting and deletion
Before outright deleting users, I strongly recommend implementing a sunsetting policy. This typically involves a series of re-engagement emails over a defined period (e.g., 30-90 days) to inactive users. This gives them a final chance to show interest and opt-in to continue receiving communications. This is a critical step to re-engage inactive subscribers and decide when to stop sending.
Once the sunsetting process is complete, and a user remains unengaged, it is time to move them to a suppression list or remove them entirely from your ESP. While temporary suppression is an option for certain segments, deleting them is often the best long-term strategy for list health and cost efficiency. I recommend a similar approach to Microsoft's handling of inactive mailboxes, where accounts are eventually deleted after a period of being on hold.
Consider the following actions based on inactivity levels:
Inactivity Period
Recommended Action
Impact on Deliverability
3-6 months
Segment into re-engagement campaigns or suppress from main sends.
Improves engagement metrics, reduces complaints.
6-12 months
Implement sunsetting flow, then move to suppression list.
Further protects sender reputation, reduces costs.
12+ months
Consider permanent deletion from ESP.
Eliminates potential spam traps and reduces ESP costs.
Ultimately, the goal is to unsubscribe inactive users and remove them, following best practices that align with both deliverability and data privacy. Understand that it can take a while for email addresses to deactivate and hard bounce, so proactive removal prevents future issues.
Avoiding common pitfalls
Benefits of proactive deletion
Improved Deliverability: Higher inbox placement rates by focusing on engaged subscribers.
Reduced Costs: Lower ESP fees by only paying for active contacts.
Enhanced Reputation: Avoidance of spam traps and blocklists (or blacklists).
One common pitfall is the fear of losing potential future engagement. While it is true that some users might become active again after a long period, the risk to your sender reputation and the financial cost of retaining them usually outweigh this slim possibility. Instead, focus on re-engagement campaigns and then safely removing those who do not respond.
Another mistake is not clearly defining inactivity. Without a consistent metric, it becomes difficult to automate the sunsetting and deletion process. I highly recommend defining what 'unengaged' means for your specific audience, whether it's no opens/clicks in X months, or no product logins in Y months, and then sticking to that definition to target inactive email users without hurting your domain reputation.
Views from the trenches
Best practices
Regularly audit your email list for unengaged subscribers.
Implement a multi-stage re-engagement (sunsetting) flow before deletion.
Define inactivity based on a combination of email engagement and product/website activity.
Automate the process of segmenting and suppressing inactive users.
Common pitfalls
Retaining inactive users for years, leading to high ESP costs and poor deliverability.
Failing to define clear criteria for what constitutes an 'inactive' user.
Not having a documented process for re-engagement and deletion.
Avoiding list cleaning out of fear of losing potential future engagement.
Expert tips
Consider segmenting truly inactive users into a 'do not mail' list rather than immediate deletion, giving a tiny window for specific, highly targeted campaigns.
Monitor hard bounce rates. A sudden increase can indicate a build-up of inactive or invalid addresses that need cleaning.
For B2B lists, regularly check for job changes or company closures, as these lead to permanent inactivity.
Use email deliverability testing tools to see how ISPs react to your emails when sent to various segments of your list.
Marketer view
Marketer from Email Geeks says: I'm trying to convince management that paying for users who haven't logged in for years is unnecessary, especially since we don't email them. We need a clear strategy for removing users from our tool, as we already filter engagement when sending.
2022-02-10 - Email Geeks
Expert view
Expert from Email Geeks says: The decision to delete inactive users truly depends on the organization's relationship with contacts and its overall email strategy. For example, a former client of an accounting practice might be kept longer.
2022-02-10 - Email Geeks
Maintaining a healthy email list
The optimal period for user inactivity before deletion from your ESP is not fixed, but generally ranges from 6 months to 2 years, depending heavily on your business model, customer relationship, and legal obligations. For most marketing lists, especially in SaaS or e-commerce, a 6-12 month threshold for complete inactivity (no opens, clicks, or product use) followed by a sunsetting process is a safe and effective strategy.
Prioritizing a clean, engaged list over a large, stagnant one will significantly improve your email deliverability, reduce costs, and ensure your messages reach the right audience. Regular list hygiene is not just good practice, it is essential for the long-term health and success of your email program.
Google, actively monitor sending behavior and recipient engagement to determine your sender reputation. A low engagement rate due to a large segment of inactive users can signal to ISPs (Internet Service Providers) that your emails are not valuable, leading them to route your messages to the spam folder or reject them outright.
