Why domain warmup makes or breaks your campaigns
A new domain is a stranger to inbox providers. Warmup is how you introduce yourself — slowly, so they trust you.
Imagine a brand-new business suddenly asking a bank for a huge loan with no credit history. The bank says no. Email works the same way: a fresh domain that blasts 100,000 emails on day one looks exactly like a spammer, and mailbox providers respond accordingly — straight to the spam folder, or blocked entirely.
What warmup actually is
Warmup means gradually increasing your sending volume over a couple of weeks. You start small, prove you send wanted email that people open, and steadily earn the right to send more. By the end, providers recognise your domain as a trusted sender.
A typical 14-day ramp
- Days 1–2: ~50 emails/day
- Days 3–4: ~100/day
- Days 5–6: ~250/day
- Days 7–8: ~500/day
- Days 9–10: ~1,000/day
- Days 11–12: ~2,500/day
- Days 13–14: ~5,000/day
After that, your full plan speed unlocks. The exact numbers vary, but the principle is always the same: slow and steady.
Warm up with your best contacts first
During warmup, send to the people most likely to open — recent, engaged subscribers. High open rates early tell providers "people want this," which accelerates trust.
GO MAILBOX warms up automatically. The day you verify your first domain, we begin ramping your daily limit through a built-in 14-day schedule — no manual work, no guesswork.
Don't skip it
Warmup is the single biggest factor in early deliverability. Rushing it can burn a domain's reputation for weeks. Take the two weeks — it pays off for years of inbox placement.