What is IP Warmup?
IP warmup is the process of gradually increasing email volume from a new IP address to build sender reputation with inbox providers before sending at full scale.
IP warmup is the practice of slowly ramping up email volume on a new IP address to establish a positive sending reputation. When you get a new dedicated IP, inbox providers like Gmail, Microsoft, and Yahoo have no history to judge whether you're a legitimate sender or a spammer. Sending too much too fast looks suspicious and triggers spam filters.
A typical warmup schedule starts with 50-200 emails per day and doubles every few days over 4-8 weeks until you reach your target volume. During warmup, you should:
• Send to your most engaged subscribers first (recent openers and clickers) • Prioritize transactional emails over marketing (higher engagement = better reputation) • Monitor delivery rates, bounces, and spam complaints daily • Slow down if you see deliverability issues
The goal is to demonstrate consistent, legitimate sending behavior. Inbox providers track patterns: Do recipients open your emails? Do they mark them as spam? Do you send to invalid addresses? Good engagement during warmup signals that you're a trustworthy sender.
Warmup applies to dedicated IPs, not shared IPs. Shared IPs are already warmed by the email service provider across all their customers.
Why IP Warmup Matters
Skipping IP warmup is one of the fastest ways to destroy deliverability. Send 100,000 emails from a brand-new IP on day one and you'll likely be blocked or heavily filtered by major inbox providers. Recovery from a bad first impression can take months. Proper warmup builds the reputation foundation that allows you to send at scale with high inbox placement. This is especially critical for businesses migrating to a new email service or launching a dedicated IP for the first time.
How Ark Handles IP Warmup
Ark's shared infrastructure is already warmed with strong reputation, so most customers don't need to worry about warmup. For high-volume senders who need dedicated IPs, we provide warmup guidance and monitoring. Our deliverability team helps you plan a warmup schedule based on your volume and audience. We track reputation signals during warmup and alert you to any issues before they become problems.
Frequently Asked Questions
How long does IP warmup take?
Typically 4-8 weeks depending on your target volume. Higher volumes need longer warmup periods. A sender targeting 1 million emails/month needs more warmup time than someone sending 50,000/month. Don't rush it—the time investment pays off in long-term deliverability.
Do I need to warm up a shared IP?
No. Shared IPs are already warmed by your email service provider. The reputation is maintained across all customers using that IP pool. This is one advantage of shared IPs for low-to-medium volume senders.
What's a good warmup schedule?
Start with 50-200 emails/day. Double volume every 2-3 days if metrics look good (high opens, low bounces, no spam complaints). Example: Day 1-3: 100/day, Day 4-6: 200/day, Day 7-9: 400/day, etc. Slow down if you see any deliverability issues.
Which emails should I send during warmup?
Start with transactional emails (password resets, order confirmations) because they have higher engagement. Then add your most engaged subscribers—people who opened or clicked in the last 30 days. Save unengaged subscribers for after warmup is complete.
What happens if I stop sending for a while after warmup?
IP reputation can decay with inactivity. If you stop sending for 30+ days, inbox providers may require you to re-establish reputation, essentially a mini warmup. Maintain consistent sending volume to preserve the reputation you built.
Can I warm up faster with a clean list?
A clean, engaged list helps warmup go smoothly, but you still can't skip the gradual volume increase. Inbox providers need to see a pattern of legitimate sending behavior over time, regardless of list quality.
Related Terms
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Hard Bounce
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Feedback Loop
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