Module 01 · Foundation
The funnel is your diagnostic instrument.
Before you write a single email, build the model that says how many sends, inboxes, and domains it takes to hit your meeting goal. This one piece of math tells you what infrastructure to buy and which numbers to stare at later.
The one idea
If you can't model it, you can't diagnose it
A cold email funnel is a stack of percentages: of every 100 emails you send, some number get delivered, of those some get opened, of those some get a reply, of those some are positive, of those some become meetings. The model is just multiplication backwards from your meeting goal to your send volume.
Once you have the model, every campaign metric maps to exactly one row. A bad bounce rate? Row one. Low reply rate with healthy delivery? Row three. The funnel is the map between symptoms and broken stages.
Build yours
The math, walked through with real numbers
Goal: 8 booked meetings per month. We'll work backwards.
Example funnel
| Stage | Conversion | Required volume |
|---|---|---|
| Meetings booked | goal | 8 / mo |
| Positive replies | 50% → meeting | 16 |
| All replies | 25% positive | 64 |
| Inboxed sends | 2% reply rate | 3,200 |
| Delivered sends | 95% inboxed | 3,370 |
| Total sends | 98% delivered | ~3,440 / mo |
| Across working days | 22 days | ~156 / day |
Read it like this: 8 meetings a month needs roughly 156 well-sent emails a day. At 30 emails per inbox per day safely, that's 5–6 inboxes minimum. Across 2–3 inboxes per domain that's 2–3 sending domains. The funnel just told you the hardware you have to buy.
2026 update Reply rates dropped roughly 30% across most B2B verticals over 2024–2025 as AI-assisted outbound got cheap. Plan for 1.5–2% reply rates, not the 3–5% from older playbooks. Adjust your model upward — you need more sends per meeting now.
Do this now
Build your own funnel model
- Write your meeting goal. Real number, monthly. If you don't have one, pick 5.
- Estimate each conversion rate. Use the example above as a starting point, then nudge based on your vertical.
- Multiply backwards. Goal ÷ each rate = required volume at each stage.
- Divide total sends by 22 days for daily volume.
- Divide daily volume by 30 emails/inbox/day for inbox count. Round up.
- Divide inbox count by 2–3 for domain count. Round up.
- Save it as a Google Sheet you'll plug actual numbers into later. This sheet becomes your diagnostic tool in Module 08.
Don't do this
The mistakes that make this model useless
Skip building it. Without the model, every metric looks like noise. You'll change copy when the bounce rate was the real problem, or buy more domains when the issue was a stale list.
Use 2022 conversion rates. Inbox filters and AI-assisted outbound have compressed every percentage. Use current numbers.
Plan for the optimistic case. Model the conservative case and you'll always have headroom. Model the optimistic case and you'll be under-provisioned at month-end.
What this rules out