Reply Rate

Also known as: response rate

Reply rate is the percentage of sent cold emails that receive any reply. It is calculated as replies divided by delivered (not sent) emails. Reply rate is the most reliable single indicator of cold-email campaign quality — opens can be inflated by image-pixel firing without real engagement; replies cannot.

Useful benchmarks: template + merge-tag B2B cold email typically lands 1-3% replies; per-lead-researched cold email lands 6-12% replies on tight ICPs; loose ICPs cut both numbers roughly in half. Reply rate includes negative replies ('please remove me') — segment positive-reply rate separately for a quality signal.

The single most common reply-rate measurement error is including auto-responders and out-of-office as replies. A clean reply-rate calculation excludes these. Mailer separates positive replies (interested, scheduled, asked a question) from negative (unsubscribed, not interested) and operational (OOO, auto-responder).