What is IP Warming?

Definition

IP Warming is a gradual process that builds trust for a new IP address by slowly increasing email volume. Instead of sending large email batches right away, you start small and increase the number over days or weeks. This careful ramp-up helps Internet Service Providers (ISPs) see your emails as legitimate. Without this process, sending too many emails from a new IP too soon can trigger spam filters, putting your messages in junk folders or blocking them entirely.

Example

For example, let’s say you are launching a big email campaign from a fresh IP. You start by sending 1,000 emails a day. Each week, you increase the volume, allowing ISPs to recognize and trust the new IP gradually. This way, your emails have a better chance of reaching the inbox and not the spam folder.

How Does IP Warming Work?

IP warming takes a steady, step-by-step approach to establish a positive sender reputation. Here’s what that looks like:

1. Start small. Begin with a low number, maybe a few hundred emails on the first day.
2. Increase volume gradually. Each day or week, add to the number. Basically, you need to avoid big jumps to keep things steady.
3. Watch engagement closely. Track opens, clicks, and bounces. High engagement improves your IP’s reputation, while low engagement can hurt it.
4. Adjust based on response. If engagement stays strong, continue to increase the volume. If it drops, slow down until it recovers.
5. Repeat until you reach your target. Continue this pattern until you are sending at your desired volume, with a trusted IP established.

This method takes patience, but it is necessary to build trust and keep emails going to the inbox.

Importance of IP Warming

IP warming matters for any large-scale email campaign. Without it, a new IP risks getting flagged by spam filters, which can harm your sender reputation. ISPs are cautious with unfamiliar IPs, especially when they send large volumes quickly. A warming schedule prevents this, allowing you to send more without risking deliverability.

Warming also improves overall deliverability. ISPs are more likely to trust an IP that builds up slowly with steady engagement. That trust boosts inbox placement and increases campaign performance. IP warming takes time, but it is a worthwhile step to reach your audience without disruptions.

Related terms

• Sender Score
• DKIM
• Email Campaign
• Throttling

Related articles

• How To Improve Email Deliverability
• Email Marketing Metrics to Track
• How to Reduce Bounce Rate