Your Subscribers Might Be Reading AI’s Version of Your Email. Here’s How to Write for It.

You spent an hour on the subject line and another on the opening paragraph. Then your subscriber saw two lines written by an AI and moved on. More and more, that’s how email gets read.

Gmail now uses Gemini to summarize messages, and Apple Intelligence does the same in Apple Mail, showing short previews of what an email says. For a busy reader, this is useful. They can scan a crowded inbox, get the gist and decide what deserves attention. For marketers, it means an AI now sits between your message and your audience, and it decides which parts are worth passing along.

Why This Matters

A subscriber who reads a summary may get what they need without opening your email. They might never see your design, your hero image or the button you tested five times. Some will still open it, but many will act on the summary alone, or ignore the email because the summary made it sound unimportant.

This also affects how you measure success. If the summary does the work, open rates drop even when your message gets through. If AI tools load your email to summarize it, opens may go up even when no one reads it. In either case, open rates say and mean less than they used to.

Write So the Summary Gets It Right

The good news is that emails that summarize well are usually just clear emails. A few habits help:

• Lead with the point. Put your main message in the first sentence or two. If the most important information is below a long intro or a big image, the AI may skip it or give it less weight.
• State the call to action in plain words. “Save 20% on fall styles through Sunday” survives a summary. “Something special is waiting for you” doesn’t. Vague teasers turn into vague summaries.
• Use real text, not text inside images. AI models read the text in your HTML. A promotion that exists only inside a graphic may not show up in the summary at all.
• Keep one main message per email. An email that covers five announcements gets squeezed into a summary that does justice to none of them. Focused emails come through with their meaning intact.
• Make the subject line, preview text and opening line agree. When all three point to the same idea, the AI has an easy, consistent story to tell.

Change What You Measure

Consider these five measures when reporting on email:

1. Click-to-open ratio: the share of people who opened an email and then clicked something. It holds up better because it compares two behaviors against each other instead of counting tracking-pixel fires, which AI tools can trigger.
2. Revenue per email sent: tracked in your ecommerce platform or CRM rather than your email tool. “The number that pays your bills.”
3. Reply rate: for emails that invite a response. AI can’t fake a reply, so a reply means a person read the email.
4. List growth vs. list decay: checked monthly, so you can tell a healthy list whose open rates are falling from a list that is actually shrinking.
5. Landing page conversion from email traffic: tag email links with UTM parameters so you can see what people do after they click.

Because opens are less reliable, put more weight on clicks, conversions, replies and revenue per send. Those numbers show whether your email led to action, and action is what counts now.

The Bottom Line

AI summaries aren’t the end of email marketing. They reward emails that respect the reader’s time. If your message is clear enough for a machine to sum up in a sentence, it’s probably clear enough for a person to act on. Put your main point first, make the next step obvious, and your email can still do its job when the reader only sees the summary.