Latest / The Email Marketing Podcast with Fexingo: Newsletters, Open Rates, and Subscriber Growth / How Email List Confirmation Emails Reduce Fake Signups
Transcript
- Lucas: Let me start with a number that stopped me this week: one B2B SaaS company found that thirty-seven percent of the email addresses collected through their single opt-in signup form were either invalid, disposable, or typo-ridden. Luna: Thirty-seven percent. That's basically a third of their list being dead weight. Lucas: Right. And those dead addresses don't just sit there. They hurt deliverability. They tank open rates. They tell mailbox providers that your list isn't curated. So today I want to talk about the simplest fix in email marketing — the confirmation email, also known as double opt-in — and why it might be the most important email you send. Luna: And before anyone says 'but it adds friction' — we're going to get into that. Because the numbers around double opt-in are actually pretty surprising. Lucas: Exactly. So the company I mentioned — I'll call them CloudFlow, a project management tool — they had a standard single opt-in form on their pricing page. Enter your email, get a free trial. Seemed fine. But when they audited their list, they found that out of ten thousand signups in a month, nearly thirty-seven hundred were fake or mistyped. Luna: Wow. So that raises a question — were those fake signups coming from bots, or just people fat-fingering their own email? Lucas: Both. They ran a quick analysis and about twenty percent were clearly bot-generated — things like 'asdf@asdf.com' or 'test@test.com.' The rest looked like real typos — 'gmial.com' instead of 'gmail.com,' that kind of thing. And even those typos are effectively dead addresses because the confirmation never reaches the intended recipient. Luna: So they switched to double opt-in — meaning after the initial signup, the user gets an email asking them to confirm. What happened? Lucas: Within thirty days, the percentage of fake or invalid signups dropped from thirty-seven percent to just under nine percent. That's a seventy-six percent reduction. But here's the trade-off — their total signup volume dropped by about twenty-two percent. Luna: Okay, so the headline number gets worse, but the quality gets better. Twenty-two percent fewer signups, but of the ones that remain, almost all are real. Lucas: And more importantly, those confirmed subscribers engaged at a much higher rate. Their open rates on subsequent campaigns went from eighteen percent to thirty-four percent. Click-through rates nearly doubled. So the argument that double opt-in kills growth only holds if you're measuring raw volume. If you measure engaged users, double opt-in actually grows your real list. Luna: I think that's the mental shift most marketers need to make. We're conditioned to optimize for top of funnel volume because it's the easiest number to put in a slide deck. Lucas: Exactly. But the cost of those fake signups goes beyond metrics. They increase your bounce rate, which hurts sender reputation. They make your list look stale to ISPs. And if you're paying for an email service provider that charges by subscriber count, you're literally paying for addresses that will never generate a single dollar. Luna: So what's the best practice for the confirmation email itself? Because I've seen some that are just a button that says 'Confirm Subscription,' and others that try to sell you something right away. Lucas: The best confirmation emails do two things. First, they make the action dead simple — one click, no captcha, no additional form. Second, they set expectations. They say 'you're confirming you want to hear from us about X, and you'll get emails roughly Y times per week.' CloudFlow actually tested a version that included the subscriber's first name in the confirmation email — pulled from the signup form — and saw a twelve percent lift in confirmation rate. Luna: That's interesting because it makes the email feel more personal, even though it's just a merge tag. But I'm guessing the bigger factor is the subject line and sender name. Lucas: Huge factor. If the confirmation email comes from 'noreply@company.com,' people are way less likely to click. CloudFlow tested sending from a real person — their marketing lead — and the confirmation click rate went from fifty-three percent to seventy-one percent. Simple change, massive impact. Luna: And what about the timing? Should the confirmation email go out instantly, or is there a case for a delay? Lucas: Instant is almost always better. The user's intent is highest immediately after they hit submit. A delay of even thirty minutes drops confirmation rates by about fifteen percent, according to some studies. CloudFlow sent theirs within thirty seconds and saw an eighty-three percent confirmation rate within the first hour. Luna: So let's talk about the elephant in the room — the fear of losing signups. If you're a media site trying to build a newsletter list fast, double opt-in can feel like a penalty. Lucas: It can be. But I'd argue that if you're building a list for long-term revenue, double opt-in is the only sustainable path. CloudFlow's raw signup volume dropped twenty-two percent, but their engaged subscriber count — people who actually opened emails in the first thirty days — went up forty-one percent. They were better off. Luna: That's a powerful stat. And it also means their list is cheaper to maintain because they're not paying for dead addresses. Plus, their deliverability improved, which helps every campaign. Lucas: Yeah, and one more thing — they also saw a drop in spam complaints. Before double opt-in, they were getting about twelve complaints per ten thousand sends. After, it dropped to two. That's a huge signal to mailbox providers that your list is clean. Luna: So for anyone listening who's still on single opt-in — what's the one thing you'd recommend they test first? Lucas: Run a thirty-day split test. Send half your new signups through a single opt-in flow, the other half through a double opt-in with a clear confirmation email. Measure not just signup volume, but open rates and click-through rates at day thirty and day ninety. The data will tell you which approach actually builds a healthier list. Luna: And that test is free to run if you're already using an email platform. Just need to set up the automation. Lucas: Exactly. And if that test confirms what CloudFlow found, you might end up with a smaller-looking list that's actually worth more. Speaking of things that are worth it — if this conversation has given you a concrete idea you can apply to your own email list, that's exactly the kind of moment where listener support makes a difference. This show is ad-free because of people who find value here and choose to chip in at buy me a coffee dot com slash fexingo. It's the smallest thing — literally the price of a coffee — and it keeps us going without sponsors. Luna: Yeah, and we love hearing that something we said actually made it into someone's workflow. So if it did, that link is there. Lucas: Alright, back to confirmation emails. One more nuance — what about the confirmation email's content beyond the button? CloudFlow tested adding a short testimonial from a current subscriber right below the confirm button. Something like 'I've been reading their weekly digest for six months — it's the only newsletter I actually open.' That lifted confirmation rate by another six percent. Luna: Social proof applied at the exact moment of decision. That's clever. And it doesn't distract from the main action — the button is still front and center. Lucas: Right. The testimonial is just a nudge. The key is not to clutter the email. Keep the design minimal — logo, one clear headline, the button, maybe a line about frequency, and then the testimonial. That's it. No links to your blog, no product upsells. That comes later. Luna: And what about the fallback? If someone doesn't confirm, should you send a reminder? Lucas: Absolutely. CloudFlow sent a single reminder after twenty-four hours. That recovered about twelve percent of unconfirmed signups. But they didn't send a third email — at that point, the person either changed their mind or the email was genuinely wrong, and further sends just hurt deliverability. Luna: So two touches — the initial confirmation and one reminder — and then drop it. That seems like a solid, low-friction system. Lucas: It is. And it keeps your list clean. The funny thing is, the confirmation email itself becomes a leading indicator. If your confirmation click-through rate starts dropping, it's a sign your signup source quality is declining. You can catch problems before they infect your main list. Luna: That's a great diagnostic tool. So the confirmation email isn't just a gate — it's a health monitor for your acquisition channels. Lucas: Exactly. And that's the takeaway I hope people walk away with. Double opt-in isn't just about verification. It's about building a list you can actually trust to deliver revenue, not just vanity numbers.