How to warm a new sending domain
Warm a new outbound domain gradually so inbox providers learn your reputation before you scale volume.
Domain warm-up is the process of increasing send volume slowly on a new domain or IP so mailbox providers can build reputation. Dumping a large cold list on day one is the fastest way to land in spam.
Why warm-up matters
New domains have no history. Providers watch early engagement — opens, clicks, spam complaints, and bounces. Sudden spikes look like abuse.
A simple warm-up plan
- Days 1–3: 20–50 highly engaged or internal addresses only.
- Week 1: Double volume if bounce rate stays low and complaints are near zero.
- Weeks 2–3: Grow toward your normal daily cadence in small steps.
- Ongoing: Cap daily volume per domain; prefer consistency over bursts.
Rules that protect reputation
- Start with your best-fit ICP, not purchased lists.
- Remove hard bounces immediately.
- Keep content consistent with what recipients expect.
- Do not rotate From domains to “reset” reputation — that often makes trust worse.
Warm-up and journeys
Branching journeys help: non-openers get fewer touches, engagers get the next step. That reduces complaint risk while volume grows.
Use OutboundOS to orchestrate the cadence while your SMTP provider handles delivery reputation. Start free when your DNS and warm-up plan are ready.