// Glossary
Domain Warmup
Gradually ramping send volume from a new domain or IP to build sender reputation before sending at scale.
Definition
Domain warmup is the practice of slowly increasing the volume of mail sent from a new domain or IP over days or weeks, starting small and ramping up as engagement accrues. Mailbox providers distrust sudden high-volume sending from unknown senders, so warming up builds reputation gradually and avoids being flagged as spam. It's a prerequisite for cold email and any new sending infrastructure.