Email Open Rate
Email open rate is the percentage of delivered emails that recipients opened. It measures how well a subject line, sender name, and send time persuade people to open a message. It is one of the oldest and most watched email marketing metrics, though tracking changes have made it less reliable than it once was.
Email Open Rate Formula
Divide unique opens by emails delivered, then multiply by 100:
Email Open Rate = (Unique Opens / Emails Delivered) × 100
A campaign delivered to 10,000 inboxes with 2,500 opens has an open rate of 25%. The denominator is delivered emails, not sent emails. Bounced messages are removed first so the rate reflects only inboxes that received the email.
Opens are tracked with a tiny 1×1 transparent image, called a tracking pixel, embedded in the email. When the recipient loads the email and the image downloads, the platform records an open. This mechanism is also the source of the metric’s biggest weakness.
Why Email Open Rate Is Less Reliable Now
Apple’s Mail Privacy Protection (MPP), launched in September 2021, broke open-rate accuracy. MPP pre-loads all email images through Apple’s servers, including the tracking pixel, whether or not the recipient actually opens the email. Every Apple Mail message registers as opened.
Apple Mail accounts for a large share of email opens, so this inflates reported open rates across the board. A 45% open rate today may reflect the same real engagement as a 22% rate in 2020. Because clicks require a deliberate action, email click rate is now a more trustworthy engagement signal for many senders.
What Is a Good Email Open Rate?
Historically, a good email open rate sat between 15% and 25%, with the all-industry average around 21%. Mailchimp benchmarks put the pre-MPP average near 21.3%. Post-MPP reported averages run higher, often 30% or more, but that reflects inflation, not better performance.
| Segment | Typical open rate | Source |
|---|---|---|
| All industries (pre-MPP) | 21.3% | Mailchimp benchmarks |
| Government | 28.8% | Mailchimp benchmarks |
| E-commerce and retail | 15.7% | Mailchimp benchmarks |
| Media and publishing | 22.2% | Mailchimp benchmarks |
Compare open rate against your own historical average and your industry, not a universal target. Track the trend over time rather than a single number, since MPP has shifted the baseline.
How to Improve Email Open Rate
- Write specific subject lines. Clear, relevant subject lines beat clever or vague ones. Personalization can lift opens.
- Optimize the preview text. The snippet after the subject line is a second headline. Do not waste it.
- Use a recognizable sender name. People open emails from names they trust. A real person or brand name outperforms “no-reply”.
- Clean your list. Removing inactive subscribers raises deliverability and keeps the rate meaningful.
- Test send times. Sending when your audience checks email raises the odds of an open.
Email Open Rate vs Click Rate
Open rate measures whether people opened the email; click rate measures whether they engaged with its content. Open rate is a top-of-funnel signal driven by the subject line. Click rate reflects the offer and body copy.
Because MPP inflates opens, many marketers now lead with click rate and conversions. Tagging your email links with UTM parameters lets you follow that engagement past the click, so Google Analytics attributes the resulting traffic and conversions to the campaign.
Frequently Asked Questions
What is a good email open rate?
A good email open rate historically fell between 15% and 25%, with the all-industry average near 21% according to Mailchimp. Post-2021 reported averages run higher due to Apple Mail Privacy Protection inflating opens. Compare against your own past campaigns and your industry benchmark rather than a fixed target.
How is email open rate calculated?
Email open rate equals unique opens divided by emails delivered, multiplied by 100. A campaign with 2,500 opens on 10,000 delivered emails has a 25% open rate. Delivered emails, not sent emails, form the denominator so bounces do not distort the result.
Why are email open rates inaccurate now?
Apple’s Mail Privacy Protection, launched in September 2021, pre-loads email images including the tracking pixel that records opens. This registers opens that never happened for Apple Mail users. Reported open rates are inflated as a result, so the metric is less reliable than clicks.
What is the average email open rate?
The average email open rate across all industries was around 21% before Apple Mail Privacy Protection, according to Mailchimp. Rates vary by sector, from about 16% in retail to nearly 29% in government. Post-MPP figures are higher but inflated.
To measure your campaign performance, use the free email open rate calculator at linkutm.