Inbox providers like Gmail and Outlook watch how recipients react to your mail. Sudden volume from a brand-new sending domain looks exactly like what a spammer does. Warming up sends the opposite signal: small, steady, welcomed sends that build trust over a few weeks.
The warm-up rhythm
The principle is simple: start small, grow slowly, and send to people who actually want to hear from you.
- Week 1 — send to your most engaged contacts only, in small batches
- Week 2 — increase volume modestly if open rates stay healthy
- Weeks 3 to 4 — keep widening to the rest of your engaged list
Protect your reputation as you grow
A few habits keep your sender reputation strong:
- Authenticate your domain with SPF, DKIM, and DMARC so providers can verify you
- Never email purchased or scraped lists
- Remove hard bounces immediately
- Make unsubscribing easy and honor it instantly
Watch the right signals
During warm-up, open rates and spam complaints tell you whether to speed up or slow down. Healthy opens and near-zero complaints mean you can grow. A dip means hold steady or pull back to your most engaged segment.
After the warm-up
Once you're warmed up, consistency is what keeps you there. A practice that emails its list on a steady rhythm stays trusted. A practice that goes quiet for six months and then blasts everyone has to warm up all over again.
Next step
Authenticate your domain first, then plan a two-to-four-week ramp to your most engaged contacts. If you'd like us to verify your domain setup and map the ramp with you, request a guided trial.