Open Rate
The percentage of delivered emails that recipients open, calculated by dividing unique opens by total emails delivered.
Open Rate Is a Vanity Metric — But You Still Need It
Open rate used to be the gold standard of email engagement. Then Apple introduced Mail Privacy Protection and blew up the measurement. Now every email opened on Apple Mail registers as “opened” whether the recipient actually read it or not. That means your reported open rate is artificially inflated.
But dismissing open rate entirely is a mistake. It still tells you directionally whether your subject lines work, whether your send times are right, and whether your sender reputation is healthy. A sudden drop in open rate — even with MPP noise — signals a deliverability problem. Treat open rate as a trend metric, not an absolute number.
How Open Rate Is Calculated
Open Rate = (Unique Opens / Emails Delivered) x 100
Note: delivered, not sent. If you sent 10,000 emails and 500 bounced, your denominator is 9,500. If 2,850 opened, your open rate is 30%.
| Email Type | Below Average | Average | Strong |
|---|---|---|---|
| Marketing campaigns | < 15% | 20-28% | 30%+ |
| Cold outbound | < 25% | 35-50% | 55%+ |
| Newsletters | < 18% | 25-35% | 40%+ |
| Onboarding/lifecycle | < 30% | 40-55% | 60%+ |
What Actually Drives Open Rate
Subject lines get all the credit, but sender name matters more. Recipients decide whether to open based on who sent the email before they read the subject line. Use a recognizable sender name — a person’s name outperforms a company name by 15-25% in B2B. Beyond that, personalized subject lines lift open rates by 10-15%, and sending at the right time (Tuesday-Thursday, 9-11 AM recipient’s local time) adds another 5-10%. Keep subject lines under 50 characters for mobile — 60%+ of B2B email is now opened on mobile devices.
Frequently Asked Questions
What is a good open rate for B2B SaaS emails?
Marketing emails: 20-30% is solid. Transactional emails: 40-60%. Cold outbound: 40-60% for well-targeted campaigns, 15-25% for broader lists. Newsletter open rates typically sit at 25-35%. But post-Apple MPP (Mail Privacy Protection), reported open rates are inflated by 10-20% because Apple pre-fetches emails, registering false opens.
Are open rates still reliable in 2026?
Less than they used to be. Apple Mail Privacy Protection, launched in 2021, pre-loads tracking pixels for all Apple Mail users, inflating open rates. About 50-60% of B2B email is opened on Apple devices. This means your true open rate is likely 10-20% lower than reported. Click-based metrics (CTR, CTOR) are now more reliable engagement indicators.
