Reply rate
The percentage of email recipients who replied — the headline metric for cold outreach and high-touch B2B email.
Reply rate is the percentage of email recipients who replied to the message, calculated as (unique replies / sends) × 100. It's the headline metric for cold outreach, sales-cadence email, and any high-touch B2B email program where the goal is starting a conversation rather than driving a click.
Reply rates vary by audience and approach. Cold outreach to well-researched, small lists can hit 15–25% on a strong opener. Mass cold outreach to broad lists rarely exceeds 2–3%. Replies-to-warm-leads sequences often hit 30%+. Cross-context comparison is unhelpful.
Reply rate has structural advantages over open rate as a metric: it's not corrupted by Apple Mail Privacy Protection, it correlates strongly with downstream pipeline value, and it's a high-effort engagement signal that ISPs reward with better deliverability. For most outbound sales programs, reply rate is the only metric worth optimizing.