What Is Cold Email Open Rate?
The percentage of delivered cold emails that are opened by the recipient, used to measure subject line effectiveness and initial deliverability.
Cold email open rate is the percentage of delivered emails that the recipient opens. It is calculated as: (unique opens ÷ emails delivered) × 100. Open rate is primarily a measure of subject line effectiveness — a prospect who opens the email has been intrigued enough by the subject line to read further. However, open rate tracking has become less reliable since Apple's Mail Privacy Protection (MPP), launched in 2021, which pre-loads email pixels and records opens even if the recipient never reads the email.
What open rates indicate
- High open rate, low reply rate: Your subject line is effective but the email body or CTA is not compelling. Fix the body.
- Low open rate: Your subject line is not getting attention, or your emails are landing in spam (in which case they may not register as opened at all). Check deliverability first, then improve subject lines.
- Very high open rate (80%+): Likely inflated by Apple MPP pre-loading. Use reply rate as the primary metric.
Benchmarks (2026)
Industry benchmarks for cold email open rates vary significantly by industry, targeting precision, and sending infrastructure quality:
- Average cold email open rate: 25–45% (plain text, well-targeted)
- High-performing campaigns: 45–60%
- Mass-blast, low-targeting campaigns: 10–20%
Note: Apple MPP inflates open rates for Apple Mail users. If your list has a high proportion of Apple Mail users, your open rate may be overstated by 10–20 percentage points.
Open rate vs. reply rate
Reply rate is a more meaningful metric than open rate for cold email because it requires a genuine human action that cannot be spoofed by tracking pixel pre-loading. Targeting reply rate as your primary conversion metric is more reliable for optimising cold email performance.
Related terms
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