Latest / The Email Marketing Podcast with Fexingo: Newsletters, Open Rates, and Subscriber Growth / Why Email List Freshness Prevents Engagement Decay
Transcript
- Lucas: So there's this stat that keeps coming up in email marketing circles: roughly twenty to thirty percent of a typical commercial email list goes completely inactive every year. Luna: That's huge. But I bet most brands just ignore it and keep sending to those people anyway. Lucas: Exactly, and that's the problem. I was looking at a case from a mid-size e-commerce brand — let's call them Coast & Co. They sell outdoor gear, about fifty thousand subscribers. At the start of the year, their open rate had slid to eighteen percent. Their click-through rate was below one percent. Luna: Oof. That's not just bad — that's deliverability-jepoardy territory. Lucas: Right. So the marketing director did something that feels counterintuitive. She applied what I'll call the six-month inactivity rule. Anyone who hadn't opened or clicked any email in the past six months got moved to a separate suppression list. They didn't delete them — just stopped mailing them. Luna: How many people are we talking? Lucas: About seventeen thousand subscribers — roughly a third of their list. And here's where it gets interesting. After that one change, their open rate jumped from eighteen to twenty-nine percent within the next quarter. Their click-through rate tripled. And their email sender score — the thing that determines whether you land in the inbox or the spam folder — went from ninety-two to ninety-eight out of one hundred. Luna: But wait — aren't they just making the numbers look better by removing the people who don't engage? It's a statistical trick, right? Lucas: That's the first objection everyone raises, and it's a fair one. But here's the thing: deliverability algorithms don't care about your total list size. They care about engagement rates. When you keep sending to people who never open, internet service providers like Gmail or Outlook start treating your emails as junk. Eventually, even your active subscribers stop seeing your messages. Luna: So pruning isn't about vanity metrics — it's about protecting the people who actually want to hear from you. Lucas: Exactly. The Coast & Co. team also measured something else: revenue per active subscriber. After the prune, it went up by twenty-two percent. Because they weren't wasting sends on dead addresses, their campaigns had more room for better content, better design, better offers for the people who cared. Luna: What about the people they suppressed? Did they ever try to win them back? Lucas: Good question. They did run a two-part reactivation sequence before putting anyone on the suppression list. The first email was a simple 'we miss you' with a ten percent discount. The second one, sent a week later, was more direct: 'if you don't engage, we'll stop emailing you.' Of the seventeen thousand, about twelve hundred people re-engaged from that sequence. Luna: So roughly seven percent came back. That's not nothing. Lucas: No, it's worth doing. But the bigger win was what happened to the remaining fifteen thousand eight hundred who stayed suppressed. Because they weren't dragging down the engagement metrics, the overall list health improved dramatically. Open rates stayed above twenty-eight percent for the next three months. Luna: Let's talk about the fear factor. A lot of marketers — especially at smaller brands — are terrified to remove subscribers because they think it's lost revenue. Lucas: And that fear is understandable. But data says the opposite. There's a well-known study from a major email service provider that looked at hundreds of brands. They found that lists that prune inactively at least once a year see thirty to forty percent higher long-term revenue per subscriber than lists that never prune. Luna: Because you're not paying to send to people who never buy, and your deliverability is better. Lucas: Right. And there's another layer: data quality. When you have a lot of inactive subscribers, your analytics get noisy. You can't trust your open rates, your click maps, your A/B test results. So every decision based on that data is suspect. Luna: So how often should a brand do this? Quarterly? Annually? Lucas: I'd say at minimum twice a year. But the best practice is to make it a rolling process. Every month, identify subscribers who haven't engaged in the last six months and move them to a suppression list. That way you're not doing a big scary purge all at once. Luna: And what about new subscribers? Should they get a grace period? Lucas: Absolutely. You don't want to suppress someone who signed up two months ago and just hasn't had time to engage. Most experts say give new subscribers at least ninety days before considering them inactive. Then extend to the six-month window for established subscribers. Luna: I want to come back to the deliverability point, because I think that's the part marketers underestimate. Can you walk us through what actually happens when you keep mailing dead addresses? Lucas: Sure. So every email you send gets scored by the receiving server. They look at things like: how many people mark you as spam, how many delete without reading, how many bounce. If the ratio of negative signals to positive signals gets too high, your sender reputation drops. Once that happens, even your best emails start going to the promotions tab or the spam folder. Luna: So it's like a credit score for your domain. Lucas: Exactly. And once it's damaged, it's hard to repair. Coast & Co. told me it took them about six weeks after the prune to see the full deliverability recovery. But they also started using a dedicated sending IP and warmed it up gradually. That helped. Luna: Let's talk about the cost side. If you're paying per subscriber on your email platform, suppressing instead of deleting might not save you money upfront. Lucas: That's true for some platforms. But most modern email service providers charge based on sends, not list size. And even if you're on a per-subscriber plan, the improved engagement usually justifies the cost. Plus, you can always delete the suppressed ones after a few months if you're confident they're not coming back. Luna: I want to ask about the psychology of the subscriber who's on the fence. If I'm someone who hasn't opened in five months, and I get a 'we miss you' email, does that feel manipulative? Lucas: It can, if it's done badly. But if the email is honest and offers value — like a genuine discount or a piece of exclusive content — most people appreciate the nudge. And if they decide they don't want to hear from you, giving them an easy unsubscribe button is respectful. It's better than them marking you as spam. Luna: So the reactivation sequence should have two goals: win back the ones who want to stay, and make it easy for the rest to leave. Lucas: Exactly. And here's a concrete tip from Coast & Co.'s playbook: in the second email, they put a one-click unsubscribe link at the very top. That actually increased their unsubscribe rate from that email, but it also reduced their spam complaints to nearly zero. Because people who wanted to leave had a frictionless exit. Luna: That's a smart trade-off. Better to lose a subscriber gracefully than get flagged as spam. Lucas: One more thing I want to mention: list freshness isn't just about removing old subscribers. It's also about how you acquire new ones. If you're buying lists or using pre-checked sign-up boxes, you're importing low-quality contacts from day one. That accelerates decay. Luna: Right — because those people never really opted in. They're more likely to bounce or mark you as spam. Lucas: Exactly. So part of a freshness strategy is making sure your acquisition channels are clean. Double opt-in, clear consent language, maybe even a welcome incentive that requires a click. That way the people entering your list are actually interested. Luna: Can we circle back to the numbers from Coast & Co.? What did the revenue look like six months after the prune? Lucas: Great question. Their monthly email revenue actually stayed flat initially, because they lost the occasional purchase from the inactive group. But by month three, revenue started climbing. By month six, it was up fifteen percent compared to the pre-prune baseline. And their cost per email sent dropped because they were sending to fewer people with higher conversion rates. Luna: So the short-term dip was worth the long-term gain. Lucas: Absolutely. And I think that's the hardest lesson for marketers: sometimes you have to shrink to grow. If these marketing conversations have sparked something you've actually used — maybe a new way of thinking about your list, or a tactic you've tried — a couple of dollars a month is genuinely what keeps these shows going. Buy me a coffee dot com slash fexingo, if you've gotten something out of them. Luna: Yeah, it's a small way to keep things ad-free and focused on what works. Lucas: Alright, so let's talk about how to actually implement the six-month inactivity rule in your own setup. Step one: define engagement. Is it an open? A click? A purchase? Most experts say a combination of opens and clicks is best, because some people read on devices that don't load images. Luna: So you need to track both, not just opens. Lucas: Right. Step two: run a query against your email platform to find subscribers whose last engagement date is more than six months ago. Step three: move them to a suppression list — don't delete yet. Step four: send a two-part reactivation sequence over two weeks. Step five: after the sequence, anyone who still hasn't engaged stays suppressed. You can delete them after another three months if you want. Luna: And for the ones who do re-engage, do you bring them back to the main list immediately? Lucas: Yes, but with a note in their profile that they were recently re-activated. That way you can track whether they stay engaged or lapse again. Some brands give re-activated subscribers a special onboarding flow to re-establish the relationship. Luna: I want to push back on one thing: what if your product is seasonal? Like a ski brand might not hear from customers in the summer. Would six months still make sense? Lucas: That's a really good nuance. For seasonal businesses, I'd adjust the window to maybe nine or twelve months, or tie it to the purchase cycle. If someone bought skis last winter and hasn't engaged since, you might still want to keep them through the off-season. But if they haven't opened an email in eighteen months, it's probably safe to suppress. Luna: So the rule isn't rigid — it should match your business reality. Lucas: Exactly. The principle is: remove people who are demonstrably disengaged over a reasonable time frame. What 'reasonable' means depends on your industry. A daily deal site might use a thirty-day window. A B2B software company might use twelve months. The key is to decide and then stick to it consistently. Luna: I also want to mention that list pruning isn't a one-time fix. It has to become part of your regular email operations. Lucas: Absolutely. Coast & Co. now runs a monthly script that identifies inactive subscribers automatically. It's baked into their workflow. And they've trained their team to think of list size not as a vanity metric, but as a health metric. A growing list is good, but only if it's growing with engaged people. Luna: So the takeaway for anyone listening: if your open rates are below twenty percent, you probably have a freshness problem. And the fix is simpler than you think. Lucas: It really is. Start with a six-month inactivity audit, run a reactivation sequence, and suppress the rest. Give it two quarters and measure the impact. I bet you'll see the same kind of improvement Coast & Co. did. Luna: Alright, great episode. I'm actually going to audit my own list this week. Lucas: Let me know how it goes. I'll be curious to hear the numbers.