The 12 most common cold email deliverability mistakes and how to fix them
Every mistake we see teams make with cold email deliverability — starting with the ones that cost the most and are the cheapest to fix.
Every cold email deliverability failure we have investigated maps to one of the mistakes below. They repeat because they are structurally easy to make.
Mistake one, the foundational one: sending from your primary domain without warmup or separation. Fix by naming an owner and writing kill criteria before you spend a dollar.
Mistake two: mistaking volume for progress. Fix by making inbox placement rate across Google and Microsoft the only weekly headline number.
Mistake three: buying tools before defining the workflow. Fix by drawing the workflow on paper first and buying only what the paper shows.
Mistake four: shipping without a quality gate. Fix by requiring a human eyeball on every artefact for the first four weeks.
Mistake five: ignoring the trigger. Cold email deliverability works when reply rate is a function of inbox placement before it is a function of copy; without a real trigger the model is guesswork.
Mistake six through twelve: cascade from the first five. Fix the top five and most of the others resolve themselves inside a month.
Frequently asked questions
AI Outreach — answered
- What is the most expensive cold email deliverability mistake?
- Sending from your primary domain without warmup or separation — because it silently degrades every downstream metric.
- Which mistake is cheapest to fix?
- Missing kill criteria. Write them in an hour and save a quarter of budget.
- Can I skip the quality gate?
- Not in the first four weeks. After the model is proven, you can automate parts of it.
- How do I know a mistake is compounding?
- Inbox placement rate across Google and Microsoft stalls or drops for two consecutive weeks. That is your alarm.
Growth Broker editorial
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