A brand-new domain has no sending history, so Gmail, Outlook and Yahoo don't know whether to trust it. If you start by sending hundreds of emails a day, most will go to spam, and the domain's reputation can be damaged for weeks. Warming up fixes this by building a history slowly.
Before you send anything
- Set up SPF, DKIM and DMARC. Without them, providers have no way to check that mail from your domain is really from you. See SPF, DKIM and DMARC explained.
- Use a real "From" name and a working reply address. Replies are one of the strongest positive signals.
- Put something on the domain's website. Even a single page helps the domain look like a real business.
A simple warmup schedule
| Week | Emails per inbox per day |
|---|---|
| 1 | 5 to 20 |
| 2 | 20 to 40 |
| 3 | 40 to 70 |
| 4+ | Increase slowly toward your target |
Most new domains need 2 to 4 weeks. The exact numbers matter less than the shape: start small and increase gradually. A sudden jump is what triggers filters.
What makes warmup work
- Opens and replies. Emails that get opened, replied to and moved out of spam teach providers that people want your mail.
- Consistency. Send every day. Long gaps followed by bursts undo the progress.
- Clean lists later. Warmup can't save a campaign sent to old or bought lists full of dead addresses. High bounce rates hurt reputation fast.
Doing it automatically
Doing this by hand means writing and answering dozens of emails a day. ZeroPhantom Warmup does it for you: add an inbox, and it sends, opens and replies to warmup emails in a slowly increasing volume, every day, until the inbox has a healthy history.