AI and the Inbox: How to Optimize Emails for Summaries and Extractions

AI isn’t just writing subject lines anymore—it’s now rewriting your emails. Yep, Apple, Google and Yahoo are taking a crack at being your copywriter (without asking for permission). With inbox summaries and automatic extractions, mailbox providers are reshaping how subscribers see your emails before they even open them.

This post breaks down what’s happening inside the inbox, what we learned from live testing and what marketers can actually do about it. You may not be able to stop AI from meddling with your emails, but you can learn how to make the most of it.

More of a visual learner? We get it. Watch the webinar recording instead.

Here’s the TL;DR

Inbox AI is rewriting your emails whether you like it or not. Apple, Gmail and Yahoo are pulling snippets, summaries and discount codes into inbox previews—sometimes making you look brilliant, other times making you look like you’re running a “100% off” sale.

• The risks: lost brand voice, skewed engagement signals and tracking chaos.
• The fixes: prioritize live text, front-load key content, use schema and annotations and preview everything before you send.

Inbox Monster’s tools help you see what subscribers actually see, so AI doesn’t rewrite your story for you.

Why AI in the Inbox Matters Now

First, let’s zoom out. Over the last few years, inbox changes have primarily focused on privacy. Remember Apple’s Mail Privacy Protection (MPP) shaking up open rates? That was all about hiding engagement.

Now, the shift is toward AI: summaries, previews and extractions that interpret your content for subscribers.

This means:

• Your carefully written preheaders may get tossed aside.
• Engagement signals could get scrambled (what’s an “open” when people read a summary instead of the full email?).
• Your witty brand voice might get lost in translation.

Beth Kittle from Twilio SendGrid summed it up perfectly: “It’s not just about deliverability anymore. AI is deciding what parts of your message actually make it to your audience.”

Marketers can’t afford to shrug this off. If your codes, offers or CTAs are getting distorted before subscribers even open the email, you’ve got a big problem.

Epic Inbox Fails (and Why They Matter)

We’ve seen plenty of inbox “oops” moments during testing. They’re funny...until you realize they can tank your email engagement.

Discount Codes Gone Wrong

Apple has a habit of yanking codes into previews. Sounds useful—until it isn’t. Imagine sending “Take 10% off” and Apple’s AI decides to preview the footer fine print: “100% off sale.” Good luck explaining that to your finance team.

"We've seen brands unintentionally advertise free products in their inbox summaries. It's a preview, but it looks like a promise." ~ Laura Sullivan, Head of Brand & Marketing, Inbox Monster

Brand Voice Distorted

AI summaries aren’t always faithful translators. Your clever copy about motivating fitness might morph into nonsense like “Apple Watch motivates...penguins are extinct.” True story from live testing.

It’s not just embarrassing—it can make your brand look careless.

Sensitive Information Exposed

Another risk: AI pulling sensitive details into previews. Account updates, payment reminders, even security alerts can be surfaced where you don’t want them.

During testing, we saw spoofing risks where a payment email from Spotify was summarized in a way that could make phishing attempts more convincing.

Apple Intelligence Summaries

Apple is leading the way with AI-powered summaries in Mail, thanks to iOS 18.

Pre-Open Previews

Instead of your carefully crafted preheader text, Apple often surfaces random snippets—codes, disclaimer text or footer copy. According to Apple, 36% of iPhones are now eligible, and 82% are on iOS 18. Translation: this is affecting a huge chunk of your list.

"That line of text you spent an hour workshopping? Apple might replace it with your unsubscribe disclaimer." ~ Laura Sullivan, Head of Brand & Marketing, Inbox Monster

Post-Open Summaries

Once someone opens, Apple sometimes generates a two- to three-sentence summary of your entire email. Sounds efficient, but it means your witty body copy might never be seen.

One big watch-out: Apple ignores alt text. If your email is mostly images with clever alt text, the summary won’t reflect it. Live text is your friend.

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Design + Deliverability Implications

The takeaway: prioritize clarity. Use live text, keep subject lines more direct and always test for brand voice loss. Cleverness is great, but it’s pointless if AI strips it out.

Gmail Gemini Summaries

Google’s AI approach looks different—enter Gemini summaries.

Limited but Growing Impact

Right now, these summaries are only available for paid Gemini or Workspace accounts. Adoption is relatively small, with about 20% using it for productivity, mostly for creative tasks.

Gemini’s Surprising Accuracy

Unlike Apple, Gemini tends to nail the summaries—even with image-heavy emails. It handles multiple topics well and rarely produces the bizarre “penguins are extinct” style bloopers.

"We were shocked at how accurate Gemini could be with summarizing complex, multi-topic messages. It's almost too good." ~ Beth Kittle, Email Deliverability Consultant, Twilio SendGrid

Deliverability and Engagement Risks

The catch: even if summaries are accurate, they change engagement. If subscribers can get what they need from a summary, they may never click through. That means skewed metrics and lost opportunities.

Automatic Extractions (Yahoo & Gmail)

Summaries aren’t the only AI trick in the inbox. Yahoo and Gmail also run “automatic extractions.”

What Are Automatic Extractions?

This is when AI pulls specific elements—images, codes, links—into the inbox preview. No opt-in, no control.

The Problems Automatic Extractions Cause

It’s not all rainbows and butterflies, unfortunately. We found some issues with automatic extractions:

• Discount codes pulled from disclaimers instead of your hero offer.
• Wrong images displayed (often the second image, not the main one).
• Click attribution errors—subscribers engage with the extraction instead of your crafted call-to-action (CTA).

"Extractions can short-circuit your tracking. The click that happens in the preview may never register in your platform." ~ Laura Sullivan, Head of Brand and Marketing, Inbox Monster

How to Take Back Control

The good news: you’re not powerless. Gmail Annotations and Schema.org markup let you guide what’s extracted.

One standout example is Hilara, which used annotation markup to ensure the preview pulled cohesive messaging instead of random snippets. It worked.

Build annotation and schema into your workflow so you’re designing for both humans and inbox AI.

See Gemini AI Summaries Before Your Subscribers Do

We’ve talked a lot about how Gmail’s Gemini rewrites your emails. Here’s the good news: you don’t have to guess what that looks like. Inbox Monster launched Gemini AI Previews inside Creative Projects, giving you a front-row seat to how Google’s AI summarizes your emails.

Instead of waiting for surprises in your subscribers’ inboxes, you can now toggle on the Gmail App (iPhone 16) preview and see the AI-generated summary for yourself. It’s like peeking behind the curtain: what will Gemini surface instead of your preheader text? What happens if your message leans too image-heavy?

Testing with Gemini Previews means you can adjust copy, design, and layout before hitting send, so you’re not writing blind.

How to Test Gemini Previews in Inbox Monster

1. Create a creative project: Upload your HTML or pull in creative from an ESP, just like you would for any other rendering test.
2. Make sure the right previews are enabled: In the client list in the creative settings, make sure the iPhone 16 Gmail is checked. This unlocks the Gemini summary preview, which will appear at the top of your preview list.
3. Review the AI summary: See exactly how Gemini rewrites your subject, preheader and body into its two- to three-sentence snapshot. Then tweak your email until the AI surfaces what you want subscribers to see.

It’s a quick step, but it can save you from the awkward moment where Gmail decides your beautifully crafted fall promo is actually about penguins.

Best Practices for Marketers

So what do you actually do about all this? Here’s the playbook.

Get More Creative With Your Email Creative

Clarity > cheekiness

Humor and wordplay are fun until AI summaries turn them into nonsense. If your subject line says “Get cozy with fall flavors 🍂” and AI rewrites it as “Pumpkin lattes taste like leaves,” that’s a problem.

Use clear, straightforward language for your subject lines and top-line copy, then weave in your personality further down in the body where it’s less likely to be misinterpreted.

Put high-value content above the “AI fold”

Think about the first 100-150 characters of your email as the danger zone. That’s where Apple and Gmail are most likely to grab summary text.

If your best offer, headline or CTA sits buried under a hero image, AI may skip it. Place your key value prop or primary CTA as high as possible so it gets surfaced correctly.

Emojis are surprisingly safe

AI might rewrite words, but it doesn’t mess much with emojis. They carry through into previews as intact little brand cues.

If you’re known for using a coffee cup ☕, rocket 🚀 or sparkle ✨, keep doing it—it’s a reliable way to preserve tone in an inbox world that wants to “neutralize” your voice.

Always combine live text with images

Image-only emails are a nightmare for AI summaries. If your hero is a big graphic with alt text like “Biggest sale ever,” Apple Mail will probably ignore it.

Instead, layer in live text headlines or captions that echo the offer. Think of it as giving AI a cheat sheet: “Here’s what you should pick up on.” This also makes your email more accessible and resilient if images are blocked.

Focus on one goal

It’s tempting to try to get your email to do everything—talk about new products, invite customers to follow you on social media and ask recipients for a review.

But just like humans, AI can get confused and misinterpret your email if there’s too much going on. Instead, focus on one core theme or goal for your email to avoid confusion from humans and bots alike.

Deliverability Considerations

Don’t assume opens and clicks mean what they used to

AI summaries mean someone might read your email without technically opening it. Or they might click on an extracted discount code in a preview, bypassing your tracked CTA. That means inflated or misleading engagement data.

The fix: look beyond vanity metrics and double down on downstream conversions (site visits, purchases, sign-ups) to gauge performance.

Re-engage continuously, not just in seasonal campaigns

AI distorts engagement signals, which can make it harder to spot when a subscriber has gone quiet. Don’t wait until holiday campaigns to clean your list.

Build in light-touch re-engagement cycles every quarter—think “We miss you” nudges, preference-center reminders, or “pick your content stream” prompts—so mailbox providers don’t assume your list is full of zombies.

Test everything, in context

Previews and summaries don’t always match what you built in your ESP. Inbox Monster’s preview tools can show you how Apple and Gmail actually display your emails. Use that intel to A/B test copy placement, schema markup and design balance. The more you test, the more you’ll understand what AI is likely to surface and how to work with it instead of fighting it.

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Don’t Let AI Rewrite Your Story

Picture this: you’ve spent hours writing the perfect email. The subject line sings, the hero image pops and the CTA is irresistible. You hit send, feeling like a rockstar, only to find Apple rewrote your headline, Gmail pulled your disclaimer into the preview and Yahoo swapped your hero image for the random stock photo in your footer.

Frustrating? Definitely. The end of email? Not even close.

AI in the inbox is just the next chapter of an old story: inbox providers changing the rules, and marketers figuring out how to play smarter.

Remember when MPP upended open rates? The marketers who adapted—who focused on clicks, conversions and better audience targeting—came out stronger. The same is true now.

Instead of panicking about what you can’t control, lean into what you can. Test how your emails render. Front-load the message you most want AI to pick up. Use schema and annotations to guide what gets extracted. Balance creativity with clarity.

"AI isn't going away. But if you know how it sees your emails, you can design for both humans and machines—and that's a huge advantage." ~ Laura Sullivan, Head of Brand and Marketing, Inbox Monster

That’s the mindset shift. Don’t think of AI summaries as your enemy. Think of them as another gatekeeper you have to win over. And the brands that adapt fastest won’t just protect their deliverability—they’ll protect their voice, their revenue and their relationship with subscribers.

Inbox Monster can’t stop Apple or Gmail from rewriting your emails. But it can give you the superpower of seeing those rewrites before your subscribers do. And once you know what the inbox sees, you can take back control of your story.

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