Email Warmup Schedule Calculator
Plan a sending warmup for a new domain or IP: ramp daily volume gradually to build reputation and see how many days it takes to reach your target.
How it works
Day d volume = start × (1 + growth%)^(d−1), capped at target · Days ≈ 1 + ln(target ÷ start) ÷ ln(1 + growth%)
Mailbox providers treat a brand-new domain or IP with suspicion, so sending a large blast on day one gets you filtered or blocked. Warmup ramps volume gradually — a steady daily percentage increase — so engagement signals accumulate and reputation builds before you hit full volume. The number of days to reach a target follows straight from compound growth: it is the exponent that grows your start volume up to the target. Slower ramps and high engagement (opens, replies, low complaints) build sturdier reputation than racing to the top.
Worked example
Starting at 50 emails a day and growing 30% daily, day 2 is 65, day 3 about 85, and so on. To reach 5,000 you need 1 + ln(5000 ÷ 50) ÷ ln(1.30) = 1 + ln(100) ÷ ln(1.30) ≈ 1 + 17.6 ≈ 19 days.
Frequently asked questions
How fast can I safely ramp?
A 20–40% daily increase is a common, cautious range for cold domains. The real limiter is engagement, not a fixed percentage: if complaint rates rise or opens fall as you scale, slow down and hold volume until the signals recover before increasing again.
Does list quality matter during warmup?
Enormously. Warm up on your most engaged, freshly confirmed recipients so early sends get high opens and few complaints. Sending warmup volume to stale or purchased addresses can tank reputation faster than a big blast would.
Do I warm the domain, the IP, or both?
Both reputations matter. On shared sending infrastructure the IP may already be warm, so you mainly warm the domain (and its DKIM/SPF/DMARC alignment). On a dedicated IP you warm both together, which is why dedicated IPs need enough steady volume to stay warm.
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This calculator is for educational purposes. Double-check important results before acting on them.