What Your Email Open Rate is Telling You … and What it Isn’t!


marketer using laptop to review email metrics

Open rates have long been used by digital marketers as a metric to determine the success of an email campaign. You just take the number of opened emails divided by the number of delivered emails. The higher that percentage, the better the results, right?

Unfortunately, not anymore.

With recent changes in technology, spam checking, and privacy policies, the open rate you see doesn’t fully reflect what’s happening today. Let’s dive in further (and even get ahead of additional changes coming next year.)

How are Open Rates Determined?

A quick refresher for those who need it … each email sent has a tracking pixel (a small image) embedded within the email. A user receives the email, opens it, and the pixel gets downloaded from the sender’s server. That download is tracked to the specific user, and … voila … you have the number of opens.

But then, it all starts to fall apart!

Why Are We Seeing Incorrect Open Rates?

Over the past couple of years we’ve started to see a significant increase in inflated open rates, due to the following:

1. Apple Mail Privacy Protection (AMPP)

AMPP was introduced in September 2021 as a new feature in the native Apple Mail app that helped users prevent others from tracking their email open behavior. In essence, Mail users have their emails pre-fetched by Apple, that tracking pixel is downloaded to Apple’s servers, and marketers see a nearly 100% open rate for that entire audience. Within six months of launch, the average open rates increased by 10%, but this could be drastically higher if your audience consists mostly of Mail users.

2. Gmail Prefetching

Like AMPP, in certain instances Gmail can prefetch images before a recipient opens their mail. Sparkpost suggests this happens when:

  • A user logs into their Gmail app on the web or mobile and has an active session.
  • An email is sent when the user has an active/open session.
  • The send email comes from Google’s IP address.

This number is much smaller than Apple’s Mail users above, but still may result in an inflated percentage of 1-2%.

3. Spam Filters

Some users have spam filters in place that may open the email during the security scanning process and thus trigger the pixel download. Many school districts and corporate offices implement this type of software to protect their servers, so you can absolutely see inflated opens here. 

4. Preview Pane

If a user views the email by hovering in a preview pane (think Gmail), this can count as an open if the pixel is rendered in that panel.

5. Forwarded Emails

If a user forwards your email, that forward can result in an open from the original tracking pixel. Not a bad problem to have, but could result in inflated total opens!

So Are Open Rates Still Valuable?

It depends! You definitely don’t want to compare your open rate to another company, as you have no idea how they are determining that number. Open rates also vary wildly based on your industry, name recognition, subject line, list quality, send time, and so much more. Instead, use your open rate as a way to A/B test your own marketing and watch for trends.

You can also change how you view your metrics and reporting. Most email platforms have introduced new metrics (which they are constantly updating). These can include any or all of the following:

  • Total Open Rate: All opens, regardless of AMPP or any other non-human interaction.
  • Pre-Cached Open Rate: The percent of messages sent in a campaign that were pre-cached by Apple MPP.
  • Projected/Estimated Open Rate: An attempt to differentiate between traceable and non-traceable openings that extrapolates the difference into what is the most likely open rate.
  • Real Open Rate: Messages opened or clicked on by a human.

Some companies also find value in dividing their open rates into categories (mobile vs. desktop, audience segments, etc.) This further helps you dive into what’s working and what isn’t.

What Changes are in the Future?

It’s hard to predict, but we do know that Gmail and Yahoo have announced they are making changes early next year to help reduce spam to their users. Within Google’s announcement are clear guidelines that include this statement regarding open rates:

  • Google does not explicitly track open rates.
  • Google isn’t able to verify the accuracy of open rates reported by third parties.
  • Low open rates may not be an accurate indicator of deliverability or spam classification issues.

While it’s not clear what will happen to our reporting, we do know there’s a movement to keep your email lists clean and your reputability score high. And there may be a shift from using open rates or click rates to determine the success of an email campaign, and instead focus on the sales, sign ups, or pageviews that result from your email sends.

Want more accurate education data to keep a clean email list? Check out what MDR can do for your data and analytics!