Email marketing is just like other digital marketing tactics: even though you start each campaign with a clear goal and strategy, you have to constantly make adjustments to remain on course.

However, you can’t improve what you can’t measure. That’s why email marketers monitor the key metrics to know what to adjust and how and when to do it. 

One of the most important email metrics is the open rate, and in this article, we’ll cover everything you need to know about this key performance indicator (including what’s going to change with recent iOS privacy updates).

Email Open Rate: The Biggest Email Metric

What’s the email open rate? An email open rate is the number of unique opens divided by the number of delivered emails multiplied by a hundred. 

For example, if you send 20 emails and five of them bounce (don’t reach the subscriber inbox), it means the number of delivered emails is 15. If out of the delivered emails, ten are opened, then the open rate is: 

(10/15)*100 = 66.67%.

The open rate is one of the key email marketing metrics. High open rates mean your subject lines are compelling readers to open the email. On the other hand, if rates are low, it could be a sign that you need to segment your subscribers better or strengthen your subject lines.

What’s the Average Open Rate?  

According to our recent Email Marketing Benchmarks report, the average open rate is 19.96%. However, open rates vary across industries and regions.  

Here is a few industries with a high email open rate: 

Industry  Average Open Rate
Nonprofit / Associations / Public Service 27.82%
Schools (K-12) 27.21%
Wellness / Fitness 25.34%
Colleges / Universities / Continuing ED 25.14%
Attractions / Entertainment / Hospitality 22.29%


Note that these are just industry averages; you can achieve higher (or lower) open rates and still run successful email campaigns. However, if your campaigns are getting open rates that are much lower than your industry’s average, it may be a sign that something needs to change.

Some of the things you could do to improve open rates include:

  • Write short yet catchy and descriptive subject lines
  • Segment your audience to send more relevant content
  • Change the frequency of emails

Why Does Email Open Rate Matter?

Email open rates can be an indicator of whether your campaign is destined for success or failure. If a campaign posts a high email open rate, it means many subscribers are reading and engaging with your emails. It justifies the need to invest time, money, and effort into that campaign. 

Lower rates, on the other hand, give you something to ponder. It could signify anything from an email deliverability issue to a content issue, but it almost always means that if you don’t make a change, your campaign likely won’t achieve its goals.

How Has the iOS 15 Update Impacted Open Rates?

While Apple’s Mail Privacy Protection (MPP) is music to the ears of privacy-conscious Apple Mail users, it seemingly spells doom for some email marketers. Here’s the gist: the Apple Mail client will now be preloading tracking pixels before recipients see their email. This will, in effect, make it seem like every email is being opened — 100% open rates for all Apple users. The new feature gives users better control over access to their data but hinders the ability of marketers to accurately track key metrics like open rates and open times. This will artificially inflate unique and total open rates for all Apple Mail users.

Instead of looking mostly to email open rates, you now need to make sure you’re also tapping into other email metrics to determine the real success of your email marketing. 

Is Open Rate The Only Metric to Measure Email Marketing Success? 

While the open rate is a vital metric, opening an email isn’t the end goal. The goal is to have as many subscribers as possible click the CTA and take the appropriate action – which could be to download a whitepaper, sign up for a service, purchase a product, or set up a demo. 

Unfortunately, open rates don’t clue you in on any of these goals. For that reason, you have to look beyond open rates and evaluate other email marketing metrics, such as:

  • Click-through rate (CTR): Out of all emails that reached the subscriber inbox, how many got a click?
  • Click-to-open rate (CTOR): Out of all opened emails, how many got at least one click? CTOR hints at how effective your email design and message is at motivating an action from subscribers. 
  • Bounce rate: Out of all sent emails, how many didn’t reach the subscriber’s inbox? This enables you to prune your email list to expunge stale email addresses to improve deliverability. On average, Benchmark Email users have a 4.31% bounce rate
  • Unsubscribe rate: It indicates the rates at which subscribers opt-out of receiving your email. Benchmark Email users enjoy a 0.02% unsubscribe rate

The bottom line is that with privacy changes, email open rates may become less reliable over time — so it’s best to take a holistic view of your email marketing campaigns and study a range of metrics rather than focusing on opens.