Key Metrics to Track During Email Warm-Up (and What They Mean)

Email warm-up isn’t just about sending emails every day. The real magic comes from the metrics that prove whether your domain is gaining trust.

If you don’t track the right KPIs, you’re flying blind. Let’s break down the most important metrics to monitor during warm-up — and what they actually mean.

📤 1. Send Count (Daily Emails Sent)

• What it is: The number of warm-up emails your domain sends each day.
• Why it matters: ESPs like Gmail and Outlook expect gradual growth. Too much, too soon = red flag.
• What good looks like: Start at 5–10/day, ramp up 10–20% weekly.

👉 Related reading: Scaling Outreach Safely: How Many Emails Per Day is Too Many?

📩 2. Inbox vs Spam Placement

• What it is: The percentage of your warm-up emails landing in inbox vs spam.
• Why it matters: Inbox placement proves your reputation is improving.
• What good looks like: <50% inbox in Week 1 → 85–95% inbox by Week 4.

👉 Related reading: From New Domain to Trusted Sender: A 30-Day Warm-Up Journey

💬 3. Reply Rate

• What it is: The % of warm-up emails that get a reply.
• Why it matters: Replies are the strongest engagement signal ESPs track. Nobody replies to spam.
• What good looks like: 20–40% replies early, then 10–15% ongoing to maintain trust.

👉 Related reading: The Science of Email Replies: Why Reply Rate Matters in Warm-Up

🛡️ 4. Domain Health Score

• What it is: An overall score combining spam hits, inbox rate, replies, and consistency.
• Why it matters: Gives you a single snapshot of your sender reputation.
• What good looks like: Healthy domains hit 80–90+ by end of warm-up.

👉 Related reading: Domain Reputation 101: How ESPs Judge Your Emails

📊 5. Bounce Rate

• What it is: % of emails sent to invalid or inactive addresses.
• Why it matters: High bounce rates kill your domain reputation fast.
• What good looks like: Under 2% during warm-up.

🚀 Final Takeaway

Warm-up isn’t guesswork. It’s a data-driven process.

Track your send count, inbox placement, reply rate, bounce rate, and domain health score. Together, they tell you whether your domain is on track to graduate from “suspicious” to “trusted.”

With AutoWarm’s dashboard, you don’t just warm up — you see your reputation improve in real time.