Reply rate

If you send 200 cold emails and get 6 replies, your reply rate is 3%. Count only real answers, not automatic out-of-office messages. Some teams count positive replies apart, meaning people who want to talk.

It is the best test of a cold message, better than open rate. Judge it after a big batch, such as 1,000 emails, not 50. If it is low, fix the list first, then the first line, then the offer. Count replies to each follow-up too, and get more repliessoon by keeping emails short.