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Metrics & Analytics

Open Rate

The percentage of delivered emails that were opened by recipients.

Definition

Open rate measures the percentage of email recipients who opened your email out of the total number of delivered emails. It is calculated by dividing the number of unique opens by the number of delivered emails and multiplying by 100. Open rate is a fundamental engagement metric that indicates initial interest in your emails. The formula is: (Unique Opens / Emails Delivered) x 100.

Why It Matters

Open rate helps you understand if your subject lines and sender name are compelling enough to get recipients to open. It is an early indicator of campaign health and can signal problems with deliverability, timing, or relevance. However, open tracking has become less reliable since Apple Mail Privacy Protection launched in 2021, which pre-fetches tracking pixels.

How It Works

Open tracking works by embedding an invisible 1x1 pixel image in the email. When the recipient opens the email and images load, the pixel is requested from a server, registering an open. This logs the timestamp, device type, and sometimes location. However, this method has limitations: some email clients block images, and Apple's privacy features pre-fetch images without the user actually opening.

Example

You send a newsletter to 10,000 subscribers. 9,800 are delivered (200 bounced). Of those, 2,450 unique recipients open the email.

Your open rate is: 2,450 / 9,800 x 100 = 25%

The following week, you try a different subject line and get 2,940 opens - a 30% open rate. You learn that personalized subject lines with the recipient's name perform 20% better for your audience.

Note: About 45% of your opens may be from Apple Mail users, which could be inflated by Mail Privacy Protection.

Best Practices

  • 1Write compelling, relevant subject lines that create curiosity or state clear value
  • 2Use a recognizable sender name that recipients trust
  • 3Test different send times to find when your audience is most active
  • 4Segment your list to send more relevant content to each group
  • 5Consider click rate as a more reliable engagement metric post-Apple MPP
  • 6A/B test subject lines systematically to improve over time

Advanced Analytics

Sequenzy provides detailed open rate tracking with Apple MPP detection to give you accurate engagement insights.

Learn More

Frequently Asked Questions

Average open rates vary by industry, typically ranging from 15-25%. B2B emails often see 20-25%, while retail might see 15-20%. Compare against your own historical rates and industry benchmarks. Note that post-Apple MPP rates may appear higher than real engagement.

Common causes include: list fatigue from oversending, decreasing relevance of content, poor subject lines, deliverability issues landing emails in spam, growing list with less engaged subscribers, or past Apple MPP inflation now correcting as you refine tracking.

Apple MPP (launched September 2021) pre-loads tracking pixels for Apple Mail users, making opens appear as 100% even if they did not actually open. This can inflate open rates by 20-50% depending on your audience. Focus more on click-based metrics as they remain reliable.