IP Warming

What is IP Warming?

A sending IP with no history is not trusted, and mailbox providers treat a sudden high-volume send from an unknown address exactly as they treat a spam run. IP warming solves this by establishing a track record before it is needed: a small volume on day one, rising on a defined schedule over two to six weeks, sent to the most engaged recipients first so the early signals the provider sees are opens, replies and no complaints. Warming applies to dedicated IPs specifically — on a shared IP you inherit the pooled reputation of everyone else sending from it, for better and worse. The related but distinct discipline is domain warming, which matters more than IP for most modern senders because reputation increasingly attaches to the sending domain. Both follow the same logic: ramp gradually, lead with your best-engaging audience, and never let volume outrun the reputation you have earned.

Why it matters

• A cold IP sending at volume is treated as a spam source regardless of content quality.
• Early sends should target your most engaged recipients, since those signals set the initial reputation.
• Only relevant on dedicated IPs — shared-IP senders inherit pooled reputation instead.

Use cases

• New dedicated IP. A four-to-six week ramp before any full-volume campaign is scheduled.
• Dormant IP restart. An IP unused for months is re-warmed rather than resumed at prior volume.
• Post-incident recovery. Volume is cut and rebuilt gradually after a blocklisting or complaint spike.