IP Warming: How to Warm Up a New Dedicated IP
IP Warming
IP warming is gradually increasing send volume on a new dedicated IP address so mailbox providers build a positive reputation for it before you send at full volume.
When you need it
IP warming applies when you're on a dedicated IP, common at higher volumes. On a shared IP, the provider manages reputation across many senders, so there's no separate IP to warm. A new dedicated IP has zero history, so the same gradual-ramp logic as email warm up applies, tied to the IP rather than the domain.
The volume bar is higher than most people assume. Nick on our team advises against dedicated IPs below 200,000 emails a month, and George, our CEO, sets the bar higher still. The guidance he published in the Email Marketing Bible, built from 908 sources, is that dedicated IPs only make sense past a million emails a month, because Gmail weighs domain reputation more than IP reputation and IP reputation carries roughly a 120-day memory.
That is why we do not hand out dedicated IPs at signup. We set one up for a user once their initial usage looks good. A new dedicated IP then needs the same careful warm-up as a custom sending domain, and the sequence for warming an email domain is the one to follow on the domain side. The warmup guides cover both tracks, and email warming is the same concept under a different name.
Shared IPs are managed for you, but they are not consequence-free. George has seen a genuine business torch a shared IP with a list that was stale or not consent-collected, which is why we hold suspect list imports for manual review before a send is released.
The ramp
Start with a few hundred sends a day to engaged recipients and roughly double every few days, watching for bounces and spam placement, until you reach target volume over two to four weeks. Sudden jumps read as spam.
A real ramp from our own infrastructure: Chong ran a clean, planned warmup of 300, then 500, then 800, up to about 10,000 a day over 14 days. The day-three send, an 800-recipient scheduled campaign, is the shape of it: small, scheduled, watched. The account behind it held a bounce rate near 1%, zero spam complaints and a reputation score around 0.99 while ramping.
George has run this at much larger scale. At SmartrMail he sent big campaigns in batches of 5,000 with a pause on any deliverability issue that tripped. His warm-up plan for a 30,000-contact list was to send to the most engaged 12,000 first, then increase in batches. Ramp the first sends and authenticate the sending domain with SPF and DKIM before volume does anything else.
Domains behave the same way. A brand-new sending domain with no reputation can see first sends to Gmail land in spam or get greylisted, and the behaviour settles as the domain warms.
One thing we will not do: some warm-up tools inject randomised non-visible HTML into each email to trick Gmail into thinking it is a personal message. George's take is that this is spam mechanics, borrowing trust the sender has not earned. We warm with real, paced volume instead. The tradeoffs across that whole category are set out in email warm up tools.
A dedicated IP is a narrow lever, and it only pays off once the rest of email deliverability is already solid. Authentication, list quality, and complaint rate decide far more of your inbox placement than which IP the mail leaves from.
Deciding whether you even need a dedicated IP, then manually pacing its ramp if you do, is a niche judgment call most senders make once and get wrong. Nitrosend is built so an AI agent makes that call and runs the ramp itself, through Claude, ChatGPT, Cursor, Codex or Gemini CLI, rather than a one-off spreadsheet exercise.
How Nitrosend handles it
Nitrosend derives exact-sender capacity from mature, clean delivery volume. Pacing shapes admitted work, and the same delivery authority rechecks health, circuits, and provider readiness before dispatch. That applies to every stream on the sender, so transactional email and marketing volume ramp under one set of rules, and sends issued through the email API pass the same health check as anything else.
FAQ
What is IP warming?
Gradually increasing send volume on a new dedicated IP so mailbox providers build a positive reputation for it before you send at full volume.
Do I need to warm up a shared IP?
No. On a shared IP the provider manages reputation across many senders. IP warming applies to dedicated IPs you control.