A new domain has zero email reputation. Send 5,000 emails on day one and you'll be blocked. Email warmup is the process of building reputation gradually so providers learn to trust your domain.
How Reputation Scoring Works
Gmail, Outlook, and Yahoo score every sending domain based on: complaint rate, bounce rate, engagement (opens/replies), spam trap hits, and sending volume consistency.
Warmup Schedule
- Week 1: 20–50/day
- Week 2: 100–500/day
- Week 3: 500–2,000/day
- Week 4: 2,000–10,000/day
- Week 5+: scale to target volume
Never increase volume more than 2x per day. Consistency matters more than speed.
What Makes Good Warmup Engagement
- Opens — shows recipients want your mail
- Replies — strongest positive signal
- Rescue from spam — manually moving to inbox sends powerful signal
- Zero complaints
Manual vs Automated Warmup
Manual works only at very low volumes. ZeroPhantom Email Warmup automates the entire process with real Gmail, Outlook and Yahoo accounts — ~2MB RAM per account, dozens of domains simultaneously.
Signs It's Working
- Gmail Postmaster: Medium or High domain reputation
- Inbox placement above 85% in seed tests
- Open rates above 20%
Automate your email warmup — instant setup →