June marks my 29th year in email marketing. While I’m semi-retired, I still send email campaigns at least twice a week for an organization I’ve been involved with for nearly 20 years—not to mention a few of my own side projects. I’ve seen a lot come and go in this space, but one trend that keeps resurfacing like a bad idea that just won’t die is the use of image-only emails.

A Little History

Back in the late ’90s, HTML emails were just starting to become standard. Internet Service Providers (ISPs) were scrambling to filter spam—and more specifically, porn spam. Filters at the time relied heavily on text content to flag suspicious emails. So, spammers, ever the innovators in the worst way, figured they could bypass these filters by embedding all their text content inside an image. Since filters couldn’t read the content of images, it worked—briefly.

But ISPs caught on and started disabling image rendering by default. Suddenly, all-image emails didn’t even display unless the recipient actively chose to “Show Images.” This standard still holds today. And in the days of dial-up, when even a 50KB file was a commitment, image-heavy emails meant painfully slow load times.

The workaround? Slicing the image into smaller parts so they’d load faster—or at least, that was the idea. Often the slices loaded out of order, or not at all, leaving emails broken and unreadable. That mess helped shape the Best Practices we started preaching in the early 2000s: balance text and images, keep file sizes small, always include alt text.

Enter: Alt Text

To help recipients decide whether they wanted to load the images, marketers started using alt text—descriptive tags in the HTML that explain what the image is. Not only did it offer a preview of the content, it also gave the marketer one more chance to reinforce a call to action or key message. It became a standard part of email marketing—and later, an important part of ADA compliance.

Good marketers still use alt text. Lazy ones don’t. And spammy senders? They never did. Alt text defeated the whole point of hiding content in an image.

Fast-Forward to Today

With high-speed internet everywhere and most people reading email on mobile, we’ve come full circle—but not in a good way. We’re now seeing a new crop of lazy, unsophisticated senders doing what amounts to the digital equivalent of shrugging: slapping one giant image into the body of an email and hitting send. No slicing, no alt text, no consideration for how the email will render on different devices or clients.

Why It’s Still a Bad Practice

Image-only emails are a conversion killer. Here’s why:

  • Blocked images = blank emails. Many email clients still block images by default. If there’s no alt text, the message might as well not exist.
  • No copy = no scanning. People skim. They don’t “read” email—they scan it. If your entire message is an image, you’ve killed scannability. You’re now just hoping someone squints at a JPEG long enough to get your message.
  • Zero accessibility. Without live text and alt tags, screen readers can’t parse your message, making your email useless to visually impaired users—and opening you up to legal risk.
  • No adaptive design. Text resizes easily. Images? Not so much. If your big graphic doesn’t scale, it breaks the layout on mobile—and that’s where most emails are read now.
  • Tracking and testing limitations. You can’t A/B test subject lines inside an image. Nor can you track individual link clicks if all your CTAs are image-based.
  • Spam filters still hate you. Image-only emails are still a red flag for spam filters. Some things never change.

Bottom Line

Sending an all-image email in 2025 is like handing someone a billboard and hoping they hang it up themselves. It’s lazy, ineffective, and ultimately bad marketing.

Text is your friend. HTML is your toolbox. Alt text is your safety net. Use them.

Don’t email like it’s 1999.