Email Warm-Up: Best Practices for New Domains
· 7 min
What is email warm-up?
Email warm-up is the process of gradually increasing your sending volume from a new domain or IP address so that inbox providers learn to trust you. Start too fast and you'll hit spam traps, trigger rate limits, and damage a reputation that can take months to rebuild. A proper warm-up takes 4–8 weeks depending on your eventual sending volume.
The warm-up schedule
Week 1–2: Send 20–50 emails per day to your most engaged subscribers — people who have opted in recently and are likely to open. Week 3–4: Scale to 200–500/day, still prioritizing engagement. Week 5–6: Ramp to 1,000–5,000/day. Week 7–8: Reach your target volume. At every stage, monitor open rates, spam rates, and bounce rates daily.
Engage your best subscribers first
Inbox providers judge your domain by how recipients respond to your mail. During warm-up, only send to people who are highly likely to open and click. This tells Google and Microsoft that your messages are welcome, which earns you preferential placement. Never send to cold or unverified lists during warm-up — one spam complaint at low volume can set you back weeks.
Authentication is required before you start
Before sending a single email from a new domain, set up SPF, DKIM, and DMARC. Without these, your messages will be rejected or quarantined regardless of your warm-up effort. Configure a DMARC policy of p=none to start (monitoring only) and tighten it to p=quarantine once your sending patterns stabilize.
Validate your list before every warm-up send
Because every bounce during warm-up has an outsized negative impact, your list must be spotless. Validate every address before the first warm-up email. Remove anything that isn't "valid" — no risky addresses, no disposables. The smaller the volume, the more each individual bounce matters to your domain's reputation score.