TL;DR
Email open rate is the percentage of delivered emails opened by recipients. B2B benchmark: 25-45% best-in-class, 15-25% median. Apple Mail Privacy Protection (2021) inflated open rates by 15-30% via prefetching — making opens unreliable as a sole engagement metric. Pair with click-through rate and reply rate for accurate engagement measurement.
What is open rate?
Email open rate is the percentage of delivered emails that recipients open. Formula: opens / delivered × 100. The metric is tracked via a transparent 1×1 tracking pixel embedded in the email — when the recipient's mail client loads the image, the open is recorded.
Open rate has been the headline email engagement metric for two decades, but its reliability dropped sharply after Apple introduced Mail Privacy Protection (MPP) in iOS 15 (Sept 2021). MPP prefetches all images — including tracking pixels — regardless of whether the user opens the email, inflating open rates 15-30% for Apple Mail users.
Why open rate matters (and its limits)
For email marketers, open rate remains the primary signal of subject-line and sender-reputation quality. Low open rates often mean either bad subject lines, bad list hygiene, or deliverability issues (spam folder). High open rates mean the audience is engaged enough to read.
Since 2022, open rate has become a secondary metric. Click-through rate and reply rate are now the more reliable engagement signals because they require actual user action that MPP cannot fake. Best-in-class email teams report all three side-by-side.
Benchmarks
| Segment | Best-in-class | Median | Concerning |
|---|---|---|---|
| B2B SaaS | 35-50% | 25-35% | <15% |
| B2B services | 30-45% | 20-30% | <12% |
| B2C / DTC ecommerce | 25-40% | 15-25% | <10% |
| Newsletter | 35-55% | 25-35% | <18% |
| Transactional | 60-80% | 45-60% | <30% |
| Cold outbound | 20-35% | 10-20% | <8% |
Benchmarks compiled from Mailchimp 2025 Email Benchmark, HubSpot 2025 Email Marketing Report, and Litmus State of Email 2025. All adjusted for MPP inflation.
Common mistakes
- Optimizing only on open rate post-MPP. MPP-inflated open rate hides whether users actually engage. Use CTR and reply rate as primary signals.
- Mixing list segments. Newsletter subscribers have 40%+ open rates; cold outbound has 15-20%. Reporting blended open rate hides which programs are working.
- Not segmenting by Apple Mail share. If 60% of your list uses Apple Mail, your open rate is structurally inflated. Segment Apple vs. non-Apple to see true engagement.
- Sender reputation issues hidden by open rate. A 40% open rate but 0.1% click rate suggests opens are being prefetched, not opened. Click rate exposes deliverability and audience-quality issues that opens hide.
Related metrics
Open rate connects to CTR, engagement rate, demand generation, lead velocity rate, MQL, and marketing attribution.
At a glance
- Category
- Marketing Metrics
- Related
- 3 terms
Frequently asked questions
What is a good email open rate?
B2B SaaS: 35-50% best-in-class, 25-35% median. B2C/DTC: 25-40% best-in-class. Newsletters: 35-55%. Cold outbound: 20-35%. Below 15% across any segment indicates deliverability or list-quality issues.
How does Apple Mail Privacy Protection affect open rate?
Since iOS 15 (Sept 2021), Apple Mail prefetches all email images — including tracking pixels — regardless of whether the user opens the email. This inflates open rates 15-30% for lists with high Apple Mail share. Open rate is no longer a reliable sole engagement metric for those audiences.
What should I use instead of open rate?
Click-through rate and reply rate as primary engagement signals — both require actual user action that MPP cannot fake. Use open rate as a secondary signal for subject-line and sender-reputation health. Best practice: report open, CTR, and reply rate together.
How do you improve open rate?
Three levers: (1) tighter list hygiene (suppress unengaged subscribers — they hurt deliverability), (2) sharper subject lines (A/B test continuously), (3) send-time optimization for the audience. Avoid quick fixes — buying lists, image-heavy emails, deceptive subject lines all hurt long-term deliverability.
Sources
- Mailchimp. 2025 Email Marketing Benchmark Report, 2025. mailchimp.com
- HubSpot. 2025 Email Marketing Report, 2025. hubspot.com
- Litmus. State of Email 2025, 2025. litmus.com
Fairview tracks email engagement alongside MQL volume and demand-gen ROI in one view — see the operating intelligence overview for the broader category.
Definitions and benchmarks reviewed by Siddharth Gangal, Founder, Fairview.
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