How to warm up a new domain or IP for cold sending?
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You've registered a fresh domain, set up your authentication, and you're ready to start sending. The one thing standing between you and the inbox right now is reputation. And a brand-new domain has none.
Mailbox providers like Gmail and Outlook treat unknown senders with suspicion. When your domain has no sending history, they have no evidence you're legitimate. The warmup process fixes that by building a track record of real engagement before you need to send at scale.
Start extremely small
Days 1 through 5, send no more than 10 to 20 emails per day. These should go to real people who will actually open and reply. Colleagues, existing contacts, and people who are expecting to hear from you are your best options. Some senders also use warmup pool tools that simulate real inbox engagement automatically.
Increase volume gradually
Every 3 to 5 days, increase your daily send volume by roughly 20 to 30 percent. So if you sent 20 emails on day 5, you're targeting around 25 on day 10, 30 to 35 by day 15, and so on. This pace feels slow. It's supposed to. Rushing is the most common warmup mistake, and it can set your domain back weeks.
A rough 6-week schedule looks like this:
- Week 1: 10 to 20 emails/day
- Week 2: 25 to 40 emails/day
- Week 3: 50 to 75 emails/day
- Week 4: 90 to 120 emails/day
- Week 5: 150 to 200 emails/day
- Week 6: 250 to 300 emails/day
These numbers are guidelines, not gospel. If you start seeing elevated bounce rates or spam folder placements, pull back and stabilize before going further.
Domain age adds friction
But a domain registered yesterday faces more scrutiny than one that's been around for 6 months, even with perfect authentication. If you can, register your sending domain 30 to 60 days before you plan to use it. Let it sit with proper SPF, DKIM, and DMARC in place, and maybe send a handful of personal emails from it during that waiting period.
Watch the signals, not just the numbers
Volume is only part of the story. What matters more is engagement. Opens, replies, and messages moved from spam to inbox all tell mailbox providers your email is wanted. Pure volume with no engagement doesn't build a positive reputation. It builds a suspicious one.
Keep a close eye on Gmail Postmaster Tools throughout your warmup. It will show you your domain reputation (none, low, medium, high) and flag any spike in spam rates before the damage compounds. If you see spam complaints creeping up, pause and review your list before continuing.
What about dedicated IPs?
If you're warming up a dedicated IP address, the same principles apply. The IP also starts with no reputation, and it also needs a gradual ramp. Domain and IP warmup happen together if you're on a dedicated setup.
If something feels off during your warmup and you're not sure whether to push through or pull back, our SOS hotline is free. No pitch, just help.
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