Latest / The Email Marketing Podcast with Fexingo: Newsletters, Open Rates, and Subscriber Growth / How Email List Preheaders Drive Open Rates
Transcript
- Lucas: So we talk a lot about subject lines on this show. But there's this other line of text that sits right next to the subject line in most inboxes — the preheader — and I think we've been underplaying it. Luna: The preheader. Which sometimes gets called the Johnson box or the preview text. And honestly, most brands treat it as an afterthought. Lucas: Right. And that's a mistake because the preheader is actually the second most visible piece of your email in the inbox. On mobile, it often gets more real estate than the subject line itself. Apple's Mail app, Gmail, Outlook — they all show it. Luna: So how much of a difference can a good preheader actually make? Do we have a number? Lucas: Yeah, Litmus did a study — they looked at hundreds of millions of emails — and they found that emails with a crafted preheader saw open rates roughly 30 percent higher than those that left it blank or auto-populated. Thirty percent. That's not tiny. Luna: Thirty percent feels huge. But I'm guessing the devil is in the detail. What makes a preheader work? Lucas: Let's start with length. Best practice is somewhere between 40 and 70 characters. Too short and you waste space. Too long and it gets truncated. On iOS, you get about 80 characters before the cutoff. On Gmail, it's closer to 100. But the sweet spot is around 60 characters — long enough to add context, short enough that most people see the whole thing. Luna: And what about content? Should it just be a continuation of the subject line? Lucas: Sometimes yes, but not always. The classic approach is to use the subject line to state the hook and the preheader to add a benefit or a time constraint. So if your subject line is 'Your Q3 playbook is ready,' your preheader could be 'Plus, early-bird pricing ends Friday.' You're giving them a reason to open now. Luna: Morning Brew does this really well. Their subject lines are often short and punchy — like 'The Fed's next move' — and then the preheader adds a tease: 'And why it matters for your portfolio.' It creates a natural curiosity gap. Lucas: Exactly. And The Hustle used to do a similar thing. They'd have a subject line like 'Why Netflix is betting on games' and then a preheader that says 'Plus: the one marketing metric you're ignoring.' That second hook is critical for people who scan quickly. Luna: What are the most common mistakes you see? Lucas: The biggest one is leaving it blank. When you do that, the email client pulls in the first line of visible text from your email, which is often something like 'View in browser' or 'If you're having trouble viewing this email...' That's a wasted opportunity. It's like putting your weakest foot forward. Luna: Right, or sometimes it grabs the alt text from an image. I've seen emails where the preheader says something like 'Logo' or 'Header image.' Not great. Lucas: Another common mistake is repeating the subject line verbatim. You're just doubling down on the same message. The preheader should complement, not mirror. And some people use generic phrases like 'Open this email' or 'Check out our latest.' That adds zero value. Luna: So what's the right strategy? Is there a framework? Lucas: I like to think of it as a three-act structure. Act one: the subject line states the topic. Act two: the preheader states the benefit or the urgency. Act three: the sender name provides the credibility. All three work together. For example, subject line: 'Your invoice is attached.' Preheader: 'Paid within 10 days to avoid late fees.' Sender: 'Accounts Payable.' Clear, actionable, credible. Luna: That's helpful. What about transactional emails versus marketing ones? Does the preheader matter as much for, say, a password reset? Lucas: It does, actually. For transactional emails, the preheader can reassure the recipient. Something like 'No action needed if you didn't request this' or 'This link expires in 24 hours.' It reduces confusion and support tickets. So yes, it's worth the effort across the board. Luna: One thing I've been wondering about: how does dark mode affect preheader visibility? Some email clients invert colors, and the preheader text might blend in. Lucas: Great question. Dark mode can mess with contrast, especially if you're using light gray text on a white background. The fix is to use high-contrast colors that work in both modes. Avoid color-only cues — like red text for urgency — because they might not render. And test, test, test. Most good email service providers let you preview in dark mode now. Luna: And accessibility? Screen readers typically read the preheader aloud. So if you cram it with emojis or all-caps, it's going to sound terrible. Lucas: Right. Keep it sentence case, use plain language, and if you use emojis, make sure they're relevant and not decorative. Screen readers will say 'smiling face with sunglasses' — which is fine once, but if you have three in a row, it's a mess. Luna: Let's talk about A/B testing. What should listeners test first? Lucas: Start with presence versus absence. Test an email with a crafted preheader against one with no preheader. That alone will likely show you the lift. Then test different lengths — 40 characters versus 60 versus 80. Then test content approaches: benefit-driven versus curiosity-driven versus urgency-driven. Each audience is different. For a B2B audience, benefit-driven might win. For a B2C audience, curiosity might win. Luna: And timing matters too. If you're sending a weekend newsletter, maybe a softer preheader works better. For a flash sale, urgency might be the way to go. Lucas: Exactly. Context is everything. There's no one-size-fits-all, which is why testing is so important. But I'd say 80 percent of the gain comes from just having a thoughtful preheader. The remaining 20 percent is optimization. Luna: I want to circle back to something you said earlier about mobile. On a phone, the preheader is often the only thing besides the subject line that a user sees before deciding to open. That makes it arguably more important on mobile than on desktop. Lucas: Absolutely. On a small screen, the subject line and preheader are fighting for attention with dozens of other emails. If your preheader adds nothing, you're giving the user a reason to swipe or delete. But if it adds value, you increase the chance of a tap. Luna: Are there any tools that help with preheader creation or analysis? Lucas: Yeah, Litmus and Email on Acid both have preheader previews. They show you exactly how your preheader will appear across different clients. Some ESPs like Mailchimp and Klaviyo have built-in fields for it. And there are even AI tools now that suggest preheader text based on your subject line. But I'd still recommend writing it yourself — you know your audience best. Luna: Speaking of writing it yourself, I want to mention something that happened to us recently. We've been putting a lot of thought into our own newsletter preheaders, and it's been interesting to see how small tweaks change open rates. It's almost like a micro-copywriting exercise. Lucas: It really is. And that kind of attention to detail is what separates good email programs from great ones. If these marketing conversations have sparked something you've actually used in your own work — whether it's a preheader tweak or a segmentation change — and you want to support the show, listeners can buy us a coffee at buy me a coffee dot com slash fexingo. It's a small way to keep this podcast ad-free and focused on practical stuff. Luna: Yeah, we really appreciate that. It helps us keep going without having to sell your data to some ad network. And now back to the preheader — one more thing I wanted to ask: do you think preheaders affect deliverability? Lucas: Indirectly, yes. Because engagement is a deliverability signal. If your preheader helps drive opens, and opens lead to clicks, then ISPs see that as positive engagement. So a good preheader can improve your sender reputation over time. It's not a direct factor like authentication, but it's part of the ecosystem. Luna: Makes sense. So the preheader is basically a small piece of real estate that can have a big impact on opens, engagement, and even deliverability, if you use it right. Lucas: Exactly. And the best part is, it's free to implement. You don't need a new tool or a bigger budget. You just need to spend five extra minutes on each email thinking about that second line. It's one of the highest roi changes a marketer can make. Luna: Alright, so to wrap up: don't leave it blank. Don't repeat the subject line. Keep it under 70 characters. Make it complement, not duplicate. And test, test, test. Lucas: Perfect summary. Next time, we're going to talk about something that's been getting a lot of buzz lately — interactive email elements like AMP and carousels. Are they worth the effort? We'll dig into some real data. Luna: Looking forward to that. For now, thanks for listening, and we'll catch you in the next one.