Cold email deliverability: a case study playbook

Names removed, numbers preserved. This is a real cold email deliverability engagement, reproduced as a playbook. Client had product-market fit, a rev team of eleven, and a stalled pipeline.

Week one: diagnosis. The stated problem was "not enough leads". The actual problem was sending from your primary domain without warmup or separation, which had been masked by inbound velocity that peaked two quarters earlier.

Weeks two to three: rebuild the target list from scratch and re-cut the trigger. Cold email deliverability works when reply rate is a function of inbox placement before it is a function of copy; the client had drifted away from that first principle.

Weeks four to six: live at 20% of previous volume, quality bar raised. Inbox placement rate across Google and Microsoft moved every week, though absolute numbers stayed modest.

Weeks seven to twelve: ramp. By week ten the number was ahead of the pre-stall baseline. By week twelve it was 40% ahead. Cost per outcome was roughly halved.

What we would repeat: the diagnosis step, the quality bar, and the weekly review. What we would kill sooner: two tools we bought in month one that added noise instead of leverage.

The client's own summary at the end of quarter one: "we thought we needed more of everything; we actually needed less of the wrong things." That is usually the lesson.