Apple Intelligence email summaries: what happens to your preview text

What are Apple Intelligence email summaries?

Apple added summaries to Mail with iOS 18.1, iPadOS 18.1 and macOS Sequoia 15.1 in October 2024. Apple's announcement said users "can see summaries without needing to open a message," and added Priority Messages, a section at the top of the inbox that "shows the most urgent emails."

Apple's Mac user guide describes three pieces:

• Inbox summaries: "A short summary automatically appears under each unread email in your inbox."
• A Summarize button at the top of an open email. If the email is part of a thread, the whole thread is summarized.
• Priority Messages: "Time-sensitive emails appear at the top of your inbox."

In iOS 18.2, Apple also added inbox categories: Primary, Transactions, Updates and Promotions. Apple describes Promotions as "emails from businesses and organizations." Users can switch back to a plain list view.

Who sees them?

Only people on devices that support Apple Intelligence. Apple's current page lists iPhone 15 Pro and later models and Macs with M1 or later, and says Apple Intelligence supports 16 languages. It also says the features don't currently work on supported devices bought in mainland China.

That's still a big group for most Shopify brands. Litmus reported Apple at 76.56% of email opens it tracked in September 2026, from over 1.5 billion opens. That number includes Apple's privacy-protected opens, so it overstates real readers, but it tells you Apple Mail is where a lot of your list opens email.

Does the summary replace my preview text?

In the inbox list, it can. Apple's Mac guide says that when you turn off "Summarize Message Previews," Mail goes back to showing the first lines of the message. That implies the summary takes the spot your preview text normally fills.

Apple doesn't publish exactly what the summary is built from. Klaviyo's take is that Apple Intelligence draws "from your incoming email content, preview text, alt text for images, and subscriber engagement history," and that "some subscribers might see Apple's summary of it instead of what your team wrote." Treat that as Klaviyo's reading, not Apple's documentation.

What Apple does confirm: users can switch summaries off. On a Mac, it's Mail, Settings, Viewing, then unchecking "Summarize Message Previews." So some of your Apple readers will see your preview text and some will see a summary. You won't know which.

What should I change in my emails?

Not much, and that's the good news. The fix is to write emails that are clear about what they are. Klaviyo's 2026 advice puts it simply: "Clarity of topic and ask is the entire game." It calls "summarizability" the "new above-the-fold."

Here's how I'd apply that:

Say the point in the first lines

If a machine has to guess what your email is about, it'll guess something bland. Open with the news: what's new, what they get, and by when. A made-up example: "The restock is live. Both flavors are back, and the bundle ships free through Sunday." A summary of that is going to say roughly the same thing.

This fits how I already think about subject lines. The most common Black Friday subject line mistake I see is being too crafty. Customers in your retention channels want to know what they'll get and where. A summary just extends that rule to the first few lines of the body.

Use live text, not text baked into images

A hero image with "40% OFF EVERYTHING" written inside it is invisible to a screen reader, and it gives a summary less to work with. Put the offer in real text right under the image, and write real alt text. Klaviyo lists alt text as one of the inputs it believes Apple reads. More on this in ecommerce email design best practices.

Don't hide the offer below a long intro

Story-first emails can still work, but if the deadline is in paragraph four, the summary may never mention it. Put the ask early and tell the story after.

Keep writing preview text

Litmus put it well before launch: "I'd still recommend writing preview text as there are email clients where this will show up." Gmail, Outlook and Apple users who turned summaries off still see it. It costs you 30 seconds. Rules for good preview text are in email subject line best practices.

Will this hurt my open rates?

There's no public data on that from Apple, Klaviyo or Litmus that I could find. Anyone quoting you a percentage is guessing.

And honestly, open rate was already a weak number on Apple devices. Since iOS 15, Apple's Mail Privacy Protection preloads images "whether the recipient opens the email or not," which Klaviyo says "artificially inflates your open rates." Litmus estimates it affects roughly 55 to 60% of all email opens.

Across 4 consumable brands and 2,897 campaigns, open rate tracked revenue at 0.32. Click rate tracked it at 0.65. Apple auto-opens pushed some segments past 85% open rates, and for one brand, open rate was negative: more opens, less money. That's why I judge emails on clicks and revenue, and why summaries don't change how I'd measure anything. The full argument is in open rate vs click rate.

Does it matter if Apple puts me in Promotions?

Apple's categories look a lot like Gmail's tabs, and the same mindset applies. Founders treat Promotions like a penalty box. It isn't. It's where marketing email lives, and your results there reflect how you've performed with your list, not a trick you missed. Chasing Primary with tricks is the wrong goal. I go through this for Gmail in the Gmail Promotions tab post.

Is plain text better for summaries?

Possibly, in the sense that a plain-text email is almost all live text, so there's more for the summary to read and less hiding in images. But don't switch formats just for Apple. Pick the format that fits the email. If you're showing a lot of product, a designed email still makes sense, as long as the key line is in real text. I compare the two in plain text vs HTML email.

What should I do first?

Pull up your last five campaigns and read only the first two lines of each. If you can't tell what the email wants from those two lines, neither can a summary. Rewrite the opening of your next send so it states the news and the ask, put the offer in live text, and keep your preview text. Then measure it the way you always should have: clicks and revenue.

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WRITTEN BY Jack White

Founder of Bardown Digital, a Chicago-based Klaviyo email and retention agency for Shopify brands. He's worked with brands doing $500K to $100M a year, with $100M+ in email-attributed revenue across them.

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