Infrastructure
What is Domain Warming?
Gradually ramping volume and engagement on a new sending domain to establish reputation.
Domain warming is the process of slowly increasing email volume from a new or newly-sending domain while generating positive engagement, so mailbox providers build a favorable reputation for that domain. Because modern filtering at Gmail and Microsoft is increasingly domain-based rather than purely IP-based, the domain's reputation often matters more than the IP's. Warming typically combines a gradual volume ramp with replies, opens, and low complaint rates, often using seed conversations or warmup networks before real campaigns begin.
Why it matters for cold email
Cold programs spin up many secondary sending domains to shield the primary brand domain, and each one must be warmed before campaigns, because an unwarmed domain hitting full volume is quickly flagged and can be hard to rehabilitate.
Related terms
Stop guessing at deliverability.
Scheduler Zero handles authentication, warmup, and sender reputation so your cold email lands in the inbox, not the spam folder.