The preheader text is no longer yours
Since iOS 26 shipped, Apple Intelligence has been quietly rewriting the inbox preview for millions of Apple Mail users. The text that appears below your subject line — the field you've spent years A/B testing — is now an AI-generated summary that Apple writes from your email body. Your preheader field is ignored.
This isn't a gradual rollout. iPhone 15 and 16 users running iOS 26 see AI summaries by default in the Promotions, Updates, and Transactions tabs. The AI reads the first 200–300 words of your email body and generates its own version. You don't control it, you can't suppress it, and the only way to influence what it says is to give it something real to work with.
What goes wrong with most e-commerce templates
Most promotional email templates are built for visual rendering, not text-first reading. A typical e-commerce promo email looks like this in raw HTML: hero image above the fold, discount headline embedded in a graphic, a few lines of "Shop now" copy, product images, footer.
The AI reads the text. If your first 200 characters of visible body text are "View this email in your browser | Unsubscribe" — which is what most legacy templates put in their pre-header text block — that's what Apple Mail's AI summarizes.
Litmus data shows the average promotional email has 38 words of actual body text before the main CTA. That's not enough for the model to generate anything useful. The output ranges from vague ("A promotional email from [brand]") to worse ("View this email in your browser").
Which templates are most at risk
Image-only templates are the worst case. If your designer locked all the copy inside image files, there's no text for the AI to read. Apple Mail generates a generic placeholder. You spent serious money on email design systems and your inbox preview says nothing.
Templates with strong preheader text but thin body copy are the second failure mode. You wrote a sharp one-liner for the preheader field. The AI ignores it and summarizes the first real paragraph instead — which in most promo emails is something like "This week only, free shipping on orders over $75." Not bad, but not what you chose to lead with.
Abandoned cart and post-purchase transactional emails are less exposed. Those tend to start with specific, text-rich body copy: "You left these items in your cart: [product name]. They're selling out." That's exactly what the model wants.
What to actually fix
The fix isn't complicated. Front-load the email body with your message.
The first paragraph of your email needs to carry the weight that the subject line and preheader used to split. Write it like a news lede: specific, direct, no decorative intro. "Your order ships Friday." "The summer drop is live — 40 new styles, early access for subscribers." "Your last order earned $12 in rewards. Here's how to use them."
Check your template architecture. The text you want the AI to summarize needs to exist as actual HTML text — not inside an image file, not inside a preheader tag. If your team uses a visual email builder, verify the first text block isn't hidden or last-loaded in the HTML. Then test it: send to an Apple Mail inbox on iPhone 15 or 16 running iOS 26, and check the inbox preview before opening. What you see is what your subscribers are seeing.
One specific thing to remove from legacy templates: "This email contains images. Please enable images to view this message." That sentence is still sitting in templates built before 2022. It's the worst possible first line for an AI to summarize.
The subject line knock-on effect
There's a secondary effect that's easy to miss. The preheader historically did complementary work alongside the subject line — extending the thought, adding urgency, completing the setup. That pairing is gone on Apple Mail.
Your subject line now stands alone for this segment of your list. Vague curiosity-gap subject lines that relied on preheader text to resolve them ("The one thing you're missing" + preheader: "Free shipping ends tonight") become ambiguous without the second line. Subject lines need to be self-contained for Apple Mail users, which is a growing share of most US e-commerce lists.
The number to keep in mind
iPhone 15 and 16 are the two most common handsets in most US subscriber lists right now. A significant portion of your list is already seeing Apple's AI summary instead of yours. Not in six months — now.
If you're seeing unexplained drops in email-attributed conversions or open rate shifts you can't tie to send time or list health, this is worth ruling out first. The free Gromerce audit gives you a clean baseline on where your revenue attribution currently stands across channels.
Your preheader text isn't coming back. The question is whether your email body is ready to replace it.
Sources: Litmus, beehiiv Blog, Stripo.email, June 2026
