Latest / The Email Marketing Podcast with Fexingo: Newsletters, Open Rates, and Subscriber Growth / How Email Design Affects Deliverability
Transcript
- Lucas: So, quick question: how much time do you spend on the visual design of your emails? Luna: If I'm honest, way too much. It's the most fun part. Selecting images, tweaking the layout, matching brand colors. Lucas: Right. And it's also the part that can, ironically, torpedo your deliverability. I've been looking at some recent data on how email design choices affect whether your message actually lands in the inbox versus the promotions tab or spam. Luna: Wait — design can hurt deliverability? I thought deliverability was all about authentication and sender reputation. Lucas: It is — those are the big ones. But design plays a role too. Let me give you a concrete example. There's a retailer, let's call them Urban Threads, who launched a big campaign last month. Beautiful email. Custom graphics, animated GIFs, a sleek two-column layout. Open rate was under 5 percent. Luna: Ouch. What happened? Lucas: Gmail flagged it as spam. They ran a post-mortem and the primary issue wasn't their authentication — SPF and DKIM were fine. It was the design. The email had almost no plain text. It was essentially one large image with text embedded, and the html to text ratio was way off. Luna: So the spam filter saw a near-empty email and thought it was suspicious. Lucas: Exactly. Most spam filters, especially Gmail, look at the ratio of text to images. If your email is mostly images, it looks like a spam tactic. The general rule of thumb is to keep your image weight under 60 percent of the total content. Ideally, aim for more text than images. Luna: But what about transactional emails? Like order confirmations — those are usually text-heavy anyway. Lucas: Right — those generally pass the test. But marketing emails are where people go overboard. Urban Threads' email was 80 percent images. That's a red flag. Luna: So what's the fix? Do we need to make boring emails? Lucas: No — not boring. But you need to include enough live text. And I mean text that's in the HTML, not embedded in images. That text is what the spam filter reads. It wants to see real content, not just a picture of content. Luna: That makes sense. So a good design might include a hero image but then have a couple of paragraphs of copy below it. Lucas: Exactly. And that's actually better for engagement too. I've seen tests where emails with a mix of text and images outperform all-image emails on click-through rates by 20 to 30 percent. Luna: I wonder if there's also a mobile issue. Images sometimes get blocked by default on mobile clients. Lucas: Absolutely. That's another argument for not relying on images. If someone has images turned off, your beautiful email becomes a blank box with broken alt text. And if your alt text is just 'image_001.jpg', you've lost them. Luna: We should talk about alt text then. I think a lot of marketers don't realize how important it is for both accessibility and deliverability. Lucas: Good point. Let's stay on that — but first, a quick aside. If these marketing conversations have sparked something you've actually used, or if you've found yourself nodding along and thinking this is the kind of straight-ahead resource you value — listener support is what keeps this show ad-free. You can help at buy me a coffee dot com slash fexingo. No pressure, just a simple way to keep the conversation going. Now, back to alt text. Luna: Yeah, I like that. And alt text is actually a deliverability factor too. Spam filters look at alt text to understand what the image was supposed to convey. If your alt text is missing or generic, that's another flag. Lucas: Exactly. You want alt text that describes the image in a natural way, and if possible, includes a relevant keyword. But don't stuff it. Just a clear description. Luna: What about code complexity? I've heard that overly complex HTML can also hurt deliverability. Lucas: Yes — that's another piece. Some email clients, especially Gmail and Outlook, have size limits. If your HTML is bloated with unnecessary divs, inline styles, or JavaScript — and by the way, don't use JavaScript, it's almost always stripped out — your email might get cut off or flagged. Luna: So keep the code clean. Lucas: Right. Use semantic HTML, minimize nested tables, and keep the total email size under 100 kilobytes if possible. Gmail clips emails over about 102KB. If it's clipped, your call to action might be hidden. Luna: That's a hard limit. So you want to test before you send. Are there tools for that? Lucas: Yeah, services like Mail-Tester or GlockApps let you check your spam score. They simulate what filters see. Urban Threads could have caught their issue with a simple test. Luna: So let's recap: keep text above 60 percent, write good alt text, clean HTML, test your spam score. Anything else? Lucas: One more: avoid using too many large images that slow load times. Some filters penalize slow-loading emails because they seem spammy. And always include a plain-text version of your email. Luna: Wait — the plain-text version is separate from the HTML version, right? I think some email services automatically generate one from the HTML, but it's often terrible. Lucas: Yes. You should create a manual plain-text version. It doesn't need to be formatted, just a readable version of your message. This helps deliverability and also ensures that subscribers with text-only clients can read your email. Luna: So in a way, good design for deliverability is really about good design for the reader. Simpler, more text, more accessible. Lucas: Exactly. It's not about making emails ugly. It's about making emails that work. And often, the cleanest, most straightforward emails perform best anyway. Luna: I've seen that with some of our own tests. The emails with a single image and a few lines of text actually had higher click-throughs than the elaborate ones. Lucas: It's counterintuitive, but the data backs it up. So next time you're tempted to create that multi-column, image-heavy masterpiece, maybe pause and think about the text to image ratio. Luna: And run a test. That's the takeaway. Lucas: Right. As we head into summer campaigns, it's worth revisiting your email templates with deliverability in mind. A small tweak could make the difference between being seen and being spammed.