Infrastructure
What is IP Warming?
Gradually increasing send volume on a new IP to build a positive sending history.
IP warming is the practice of starting with a low daily volume from a new or cold sending IP and increasing it on a schedule over days or weeks. Mailbox providers track sending behavior per IP, so a sudden burst from an address with no history looks like spam, whereas a gradual ramp lets the IP accumulate positive engagement signals. Warming is most relevant for dedicated IPs, since shared IPs inherit the pooled reputation of every sender on them.
Why it matters for cold email
Cold email at scale needs new IPs and inboxes, and skipping the ramp is one of the fastest ways to get filtered or blocked, so a disciplined warming schedule paired with real engagement is what makes sustained volume possible.
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.