How does sending email to inactive contacts affect deliverability?
Matthew Whittaker
Co-founder & CTO, Suped
Published 9 Aug 2025
Updated 13 Oct 2025
5 min read
Sending emails to inactive contacts is a common practice that can have significant, often negative, consequences for your email deliverability. It might seem harmless, or even like a necessary step to re-engage past subscribers, but without the right approach, it can severely damage your sender reputation and lead to your emails consistently landing in the spam folder.
The core issue revolves around how mailbox providers interpret your sending habits. When a large portion of your audience doesn't open, click, or interact with your emails, it signals to ISPs that your content isn't relevant or desired. This perception can quickly degrade your sending reputation, impacting your ability to reach even your most engaged subscribers.
Defining inactive contacts
Before diving into the impact, it's crucial to define what an "inactive contact" truly means for your specific sending patterns. Inactivity isn't a one-size-fits-all metric. For some, it might be a contact who hasn't opened an email in three months, while for others, it could be six to eight months, or even longer for less frequent senders.
An overly aggressive definition, such as marking contacts inactive after just one month of no engagement, can be detrimental. Many people may still want your emails but might not open every single one, often heading directly to your website. Relying solely on open rates can lead to misclassifying genuinely interested subscribers as inactive. It's important to consider broader engagement signals, like clicks, website visits, or purchases.
Tailoring your definition of inactivity to your audience and content frequency is key. A service that sends daily updates will have a different inactive threshold than one that sends monthly newsletters. Understanding this nuance can help you avoid prematurely removing subscribers who still value your communications.
Degrading your sender reputation
The primary way sending to inactive contacts impacts your deliverability is through its effect on your sender reputation. Mailbox providers, such as Gmail, Yahoo, and Outlook, monitor how recipients interact with your emails. Low engagement, high bounce rates, and increased spam complaints are all negative signals.
Sending to engaged contacts
When you focus on active subscribers, you typically see:
Higher open rates: Indicating content relevance and recipient interest.
Increased click-through rates: Showing that your calls to action resonate.
Fewer spam complaints: Confirming your emails are wanted.
Conversely, targeting inactive subscribers often results in:
Lower engagement rates: Directly impacting your sender reputation.
Higher bounce rates: Due to dead or abandoned email addresses.
Increased spam complaints: From recipients who no longer recognize or want your emails.
Risk of hitting spam traps: A critical hit to your reputation.
When your overall campaign metrics dip due to a segment of inactive users, ISPs take notice. They might start filtering more of your emails to spam, not just for the inactive segment but for your entire list. This can undermine all your efforts to maintain good deliverability.
The risks of re-engagement
Attempting to re-engage inactive contacts comes with distinct risks. These risks escalate the longer a contact has been inactive. Here are the main concerns:
The threefold risk of inactive contacts
Dead email addresses: Over time, people abandon email accounts. Sending to these addresses results in hard bounces, which ISPs see as a negative signal about your list quality. A sudden spike in bounce rates can harm your deliverability immediately. To understand more, explore what happens to your deliverability with bounces.
Spam complaints: Recipients who haven't heard from you in a long time may forget they subscribed or no longer want your emails. Their most likely action, especially if they don't see an easy unsubscribe, is to mark your email as spam. High spam complaint rates are one of the strongest negative indicators to ISPs.
Spam traps: Old, dead email addresses are often repurposed as spam traps by ISPs and anti-spam organizations. Hitting a spam trap is a severe blow to your sender reputation and can lead to immediate blocklisting (blacklisting).
These risks highlight the importance of careful list hygiene and segmentation. Blindly sending to an old list can erase months, or even years, of building a positive sender reputation. It's crucial to mitigate these risks when considering re-engaging inactive subscribers.
Strategies for managing inactive lists
Managing your inactive list effectively is about striking a balance between re-engagement attempts and protecting your sender reputation. Here are some strategies:
Gradual re-engagement campaigns: Instead of a large blast, send small volumes of emails to inactive segments over weeks or months. Mix these with your regular, highly engaged sends to average out metrics and minimize impact.
Segment your inactive users: Differentiate between those inactive for 3 months, 6 months, a year, and longer. The strategy for someone inactive for 6-8 months should be more cautious than for someone inactive for 1-3 months.
Clear re-introduction: If you're contacting someone after a long period, remind them who you are and why you're emailing. Offer clear value and an easy way to update preferences or unsubscribe. Learn more about safely messaging inactive addresses.
Sunset inactive subscribers: At some point, it's best to remove or suppress contacts who remain unengaged despite your re-engagement efforts. This protects your list quality and reputation. Here are the best practices for sunsetting inactive email subscribers.
Crucially, implement DMARC to gain visibility into your email ecosystem. DMARC monitoring helps you see authentication failures and how emails are being handled by receiving servers, providing data that guides your list management and re-engagement strategies. Suped offers the most generous free plan for DMARC reporting and monitoring on the market. It's an indispensable tool for protecting your email program.
Maximizing your email performance
The long-term health of your email program relies heavily on maintaining a clean and engaged subscriber list. While the temptation to try and re-engage every contact is understandable, prioritizing quality over quantity is paramount. By understanding the risks, implementing smart segmentation, and carefully planning your re-engagement attempts, you can protect your sender reputation and ensure your emails reach the inbox.
Regularly monitoring your deliverability metrics and taking proactive steps to manage inactive contacts will not only improve your inbox placement but also optimize your email marketing ROI. Maintaining a healthy email list is an ongoing effort that pays dividends in sustained deliverability and successful campaigns.
Views from the trenches
Best practices
Implement gradual re-engagement campaigns over weeks to spread the volume.
Mix a very small percentage of inactive contacts with highly engaged sends.
Define 'inactive' based on broad engagement, not just open rates, considering website visits.
Regularly monitor DMARC reports to spot authentication issues from inactive sends.
Segment inactive users based on duration of inactivity for targeted approaches.
Common pitfalls
Sending large, sudden campaigns to a long-inactive list without prior segmentation.
Defining contacts as inactive too aggressively, like after only one month.
Ignoring rising bounce rates and spam complaints from re-engagement attempts.
Failing to remove truly unengaged subscribers after re-engagement efforts.
Not clearly re-introducing yourself in emails to long-inactive contacts.
Expert tips
Focus on the number of recipients in high-risk campaigns, aiming for less than 1% of total sends.
Develop a clear strategy for re-engagement, including what happens if they react or don't.
ISPs consider addresses 'dead' after many months of no login, not just a few weeks.
Leverage frequency policies that adjust sending based on fluctuating engagement levels.
Prioritize list hygiene to prevent hitting spam traps and maintain a strong sender reputation.
Marketer view
Marketer from Email Geeks says: The impact on deliverability depends on how long contacts have been inactive, for example, 3 months versus 6 months. Many people find success by mixing small numbers of inactive contacts with engaged senders to help balance campaign metrics.
2023-09-01 - Email Geeks
Marketer view
Marketer from Email Geeks says: When re-engaging, focus on the number of recipients rather than the number of campaigns. Sending a huge campaign to a predominantly inactive list can cause problems. Aim for a very small percentage, perhaps under 1%, of 'high-risk recipient mails' in any given send, even if it means taking weeks to reach them all.
