Latest / The Email Marketing Podcast with Fexingo: Newsletters, Open Rates, and Subscriber Growth / How Email List Cold Starts Kill Engagement
Transcript
- Lucas: Luna, I want to talk about something that I think is quietly wrecking a lot of email programs — especially for newer lists or lists that just went through a big growth spurt. Luna: Okay, I'm listening. What's the problem? Lucas: It's what I'm calling the cold-start problem. You know how when you start a new email newsletter or run a big lead magnet campaign, you suddenly get hundreds or thousands of new subscribers at once? Luna: Yeah, and everyone gets excited. You want to send them your best stuff right away to hook them. Lucas: Exactly. And that is exactly the wrong move. When you blast a brand-new subscriber with your regular cadence — say three emails a week — from day one, their engagement actually tanks faster than subscribers who were eased in slowly. Luna: Wait, so you're saying the people who get fewer emails at first end up more engaged later? Lucas: That's the data. I was looking at a case from a mid-size B2C retailer — they sell kitchen gadgets — who tested this. They split their new subscribers into two groups. Group A got the standard three-emails-per-week onboarding. Group B got a gradual ramp: one email the first week, two the second, three by week four. Luna: And what happened? Lucas: After 90 days, Group B had open rates 34 percent higher than Group A. And click-through rates were nearly double. The cold-start group — Group A — actually saw open rates decline steadily from week two onward, as if they were already fatiguing people. Luna: That's wild. So the very thing you think is maximizing engagement — send more, send fast — is actually burning people out before they even form a habit. Lucas: Right. And there's a technical layer here too. Mailbox providers like Gmail and Outlook are watching how your domain behaves with new recipients. If you suddenly send a high volume to a bunch of addresses that have never seen you before, the algorithm flags you as potentially suspicious. Your emails might land in spam or get filtered into a promotions tab. Luna: So it's not just about subscriber psychology. It's about deliverability from the very first send. Lucas: Exactly. And that's part of why cold-start engagement drops. The mailbox provider doesn't trust you yet, so your emails don't reach the primary inbox. The subscriber never even sees them, so they don't open. That further degrades your sender reputation. It's a downward spiral. Luna: So what does a good warm-up sequence actually look like? You mentioned one email the first week. Is that the standard? Lucas: It depends on your list size and your sending history. But a general rule of thumb I've seen work well is to start with one email in the first seven days. That first email should be a true welcome — not a sales pitch. Set expectations for frequency and content. Then week two, send two. Week three, three. By week four, you're at your normal cadence. Luna: And what about the content itself during that ramp-up? Should it be different from what you'd send a regular subscriber? Lucas: Great question. The content should be oriented around building familiarity. Think of it like a first date. You don't lead with 'buy my stuff' — you lead with 'here's what I'm about, here's the value you'll get, here's a useful tip.' That builds trust. Then by the time you're at full frequency, the subscriber has already decided you're worth their attention. Luna: I've also seen brands use a preference center during the welcome email — asking subscribers how often they want to hear from you. That seems like a smart move because it gives the subscriber control. Lucas: Yeah, that's a great addition. It also signals to mailbox providers that you're respecting user choice, which can help with deliverability. But the key insight here is that the cold-start problem is real and it's measurable. If you're not gradually warming up new subscribers, you're leaving engagement — and revenue — on the table. Luna: And it's not just new lists. If you run a big acquisition campaign and suddenly double your list overnight, you're essentially cold-starting a huge chunk of your audience. Lucas: Right. The same logic applies. You might have a strong sender reputation, but if you suddenly send to a bunch of new addresses, you still need to warm them up. Some senders even do a staged rollout — they drip new subscribers onto their main list over a few weeks rather than importing them all at once. Luna: That makes a lot of sense. So what's the one thing you'd tell someone to check tomorrow? A quick diagnostic. Lucas: Look at your open rates for subscribers who joined in the last 30 days versus subscribers who have been on your list for 90 days or more. If the new ones are significantly lower, you've got a cold-start problem. Then check your sending frequency for those first 30 days — are you ramping up gradually or going full blast? Luna: That's a concrete first step. And it's something a lot of marketers don't even think to segment by. Lucas: I know this because we've been diving into a lot of email metrics lately for these episodes, and honestly, the more we dig, the more I realize how much of this stuff is just not obvious until you look at the data. And that's part of why we do the show the way we do — no ads, no sponsors, just real conversations about what actually works. Luna: Yeah, it's been great to have the freedom to follow the data wherever it leads. And if listeners find these marketing conversations useful, you can support the show and keep it ad-free by visiting buy me a coffee dot com slash fexingo. Lucas: Exactly. No pressure, but it does help us keep doing deep dives like this. So back to the cold-start problem — one more thing I think is worth mentioning. Luna: Please. Lucas: If you have an existing list that's gone cold — say you haven't emailed in six months — treat it the same way. Don't blast everyone at full frequency. Do a re-engagement campaign first, then ramp up gradually for the people who re-engage. Otherwise you'll just accelerate the list decay. Luna: That's a really good point. The cold-start problem isn't just for brand-new lists. It's any time you add a significant number of unengaged addresses to your send stream. Lucas: Exactly. And I think the broader lesson here is that email is a relationship channel, not a broadcast channel. Treating new subscribers like strangers who need to be won over, rather than customers who need to be sold to immediately, pays off in the long run. Luna: I love that framing. Alright, next episode we'll talk about something I've been curious about — how to handle email list churn when you're growing fast. Stay tuned.