AI is changing how inboxes filter and surface content, privacy changes have made open rates unreliable, and the old email marketing playbook isn't working the way it used to. When we polled attendees at our 2026 Marketing benchmark webinar, this showed up clearly: The biggest email challenge heading into 2026 was engagement.

Our 2026 Marketing benchmark report confirms it — five years of trend data show the gap between top performers and everyone else widening year over year. In the webinar, Brady Hartman and Caroline Henno from Acoustic's Professional Services team unpacked the findings and shared practical guidance on how to close that gap.

The common thread across everything they covered: Relevance over volume. The brands pulling ahead aren't sending more — they're sending smarter. Here are five tips from the session:

1. Optimize your emails for AI summaries

AI isn't just filtering your emails anymore. It's interpreting them. Gmail, Apple Mail, and other providers now generate AI summaries that display key information — the offer, the price, the deadline — directly in the inbox view. These summaries can satisfy a subscriber's curiosity without them ever opening your message. If the summary is accurate and enticing, it might be enough to drive the open. If it's vague or misleading, it becomes the reason they skip you entirely.

The fix: Put your key message or CTA in the first one or two lines, not buried after a header image. Don't hide important content in images. And preview how your email gets summarized before you send.

2. Think about personalization in four dimensions

Personalization means more than dropping a first name into the subject line. Four drivers that determine whether someone clicks after they open:

• Past behavior: Purchase history, browse and cart abandonment, on-site search.
• Future state: Intent signals and propensity predictions. How close are they to converting?
• Present state: Current sentiment, journey position, lifetime value. Are they happy with you right now?
• Timing: Is this the right moment to reach them?

A simple example: You wouldn't send a promotion to someone who just filed a support complaint. When you account for all four factors, click-to-open rate (CTOR) takes care of itself.

3. Know when not to send an email

Sometimes the problem isn't the message or timing. It's that you sent an email at all. Knowing when not to send an email is just as important as knowing what to put in it.

If a customer responded to a survey via SMS, following up by email feels disconnected. If they booked a flight through your app, a push notification makes more sense. If an order came through WhatsApp, continue that conversation in WhatsApp.

Matching the follow-up channel to where the interaction happened reduces friction — and when the experience feels continuous, unsubscribes drop.

4. Rethink how you measure unsubscribes

Unsubscribes have risen 22% over the past five years. That sounds alarming, but consider the alternative.

An opt-out is a neutral interaction — it doesn't hurt your sender reputation. A spam complaint is a real negative signal. Making it easy to unsubscribe is always the right move, because the alternative is getting marked as spam.

Gmail's "Manage subscription" page now lets users unsubscribe from all emails from a domain in one click. Easy opt-outs are the expectation, not a nice-to-have.

Preference centers help you retain subscribers who would otherwise disappear. Offer snooze options — 30, 60, or 90 days. Let subscribers choose content categories or adjust frequency.

5. Clean your list before it cleans you out

It feels counterintuitive — why would you shrink your list after all the work you've put into growing it? But every unengaged contact you're mailing is working against you. They drag down your open rate, contribute to soft bounces, and can lead to spam complaints that damage your sender reputation.

A good rule of thumb: If a contact hasn't done anything — no opens, no clicks, no logins, no purchases — in the last 90 days, it's time to re-engage them with a win-back campaign. If that doesn't work, let them go.

Watch the webinar on demand

These five tips are just a preview. Brady and Caroline covered a lot more ground in the webinar — including why GDPR regions consistently outperform, how to filter bot clicks from your reporting, and detailed breakdowns by industry and region. Watch the 2026 Marketing benchmark webinar on demand.

And if you haven't already, download the full 2026 Marketing benchmark report for detailed breakdowns by industry and region.