Domain and/or IP Warm-up Guide
A thought-out warm-up plan limits greylisting and delivery throttling, as well as helping establish a good domain and IP reputation.
As your volume increases, you'll need to monitor your bounce rate to ensure it remains below 4%, and your spam rate below 0.08%. An increase in these rates would be a sign that your warm-up plan needs to be slowed down and an investigation into the root causes of the increases started.
Following these rules and metrics will establish a good domain reputation.
Existing domain
Section titled “Existing domain”If you're already sending from an existing domain with established reputation and volumes, you can use the following guidelines to start sending with Resend.
| Day | Messages per day | Messages per hour |
|---|---|---|
| 1 | Up to 1,000 emails | 100 Maximum |
| 2 | Up to 2,500 emails | 300 Maximum |
| 3 | Up to 5,000 emails | 600 Maximum |
| 4 | Up to 5,000 emails | 800 Maximum |
| 5 | Up to 7,500 emails | 1,000 Maximum |
| 6 | Up to 7,500 emails | 1,500 Maximum |
| 7 | Up to 10,000 emails | 2,000 Maximum |
New domain
Section titled “New domain”Before you start sending emails with a brand new domain, it's especially important to have a warm-up plan so you can maximize your deliverability right from the start.
| Day | Messages per day | Messages per hour |
|---|---|---|
| 1 | Up to 150 emails | |
| 2 | Up to 250 emails | |
| 3 | Up to 400 emails | |
| 4 | Up to 700 emails | 50 Maximum |
| 5 | Up to 1,000 emails | 75 Maximum |
| 6 | Up to 1,500 emails | 100 Maximum |
| 7 | Up to 2,000 emails | 150 Maximum |
Warm-up calculator
Section titled “Warm-up calculator”Use the calculator below to generate a personalized warm-up schedule based on your specific needs. Enter your target volume, timeline, and domain type to get a custom plan.
The guide is meant as a general plan, but always pay careful attention to your deliverability and adjust accordingly. If you have specific questions, please reach out to us.
Warming up your Dedicated IP with Resend
Section titled “Warming up your Dedicated IP with Resend”In order for a Dedicated IP to be beneficial or useful, you first need to establish a certain sending volume and patterns. Once you've established this volume and these patterns, our Support team can set it up for you.
Resend provides an automatic warm-up process so that you can focus on sending.
Learn more about requesting a Dedicated IP.
Third-party warm-up services
Section titled “Third-party warm-up services”Email deliverability is important, and it can be tempting to use services promising quick fixes. However, using tools that artificially boost engagement can harm your long-term sender reputation. These services often rely on manipulating anti-spam filters, which can backfire as email providers like Gmail adjust their systems.
Instead, focus on sustainable practices, such as sending relevant content, maintaining a clean list, and using proper authentication. These methods build trust with email providers and improve your deliverability over time.