A new sending domain has zero reputation with receivers. Send 10,000 emails on day one and Gmail throttles you into oblivion for weeks. Warm it up right and you're at full volume in 14 days with a clean reputation you can actually maintain.
Before you send anything
Get the DNS foundation right first. If any of these are missing, warming up sends bad signals from day one:
- SPF record pointing to your provider
- DKIM record published and verified
- DMARC record at
p=noneminimum - Consistent From address that matches the domain
- Reasonable MX record (even if the domain doesn't receive)
The 14-day ramp
Each day, send to your most engaged recipients first. Opens and replies drive positive reputation faster than volume alone.
| Day | Volume | Target |
|---|---|---|
| 1 | 50 | Internal team + power users who reply |
| 2 | 100 | Same segment, different content |
| 3 | 250 | Top-tier customers |
| 4 | 500 | Active users (last 30 days) |
| 5 | 1,000 | Active users, broader |
| 6–7 | Weekend hold | Watch the numbers, don't push |
| 8 | 2,000 | All active |
| 9 | 5,000 | Active + semi-active |
| 10 | 10,000 | Broader engagement pool |
| 11 | 20,000 | Approaching normal volume |
| 12–14 | Full volume | Steady-state |
Watch these numbers daily
- Bounce rate — must stay < 3%. If it climbs, stop and clean the list.
- Complaint rate — must stay < 0.1%. Above that, you're heading for blocklist.
- Open rate — a leading indicator; sudden drops mean you started landing in spam.
- Postmaster tools — Google Postmaster and Yahoo Sender Hub give daily reputation data. Check daily during warmup.
If you break the ramp
Sent 50k on day 3 instead of 250? You now have a cold-domain reputation problem. Stop sending for 24 hours. Resume at the day-1 volume and re-ramp from scratch. It's worth losing a week of sending compared to spending a month recovering from a spam-folder classification.
Steady-state maintenance
Once you're warm, don't regress. A domain that sits idle for 30+ days loses warm-up progress. If you're sending marketing broadcasts, keep at least a small transactional volume flowing every day — even 100 messages — to hold reputation.