Deliverability
Domain and/or IP Warm-up Guide
Learn how to warm up a domain or IP to avoid deliverability issues.
Warming up a domain or IP refers to the practice of progressively increasing your sending volume to maximize your deliverability. The goal is to send at a consistent rate and avoid any spikes in email volume that might be concerning to inbox service providers.
Whenever you change your sending patterns—whether because you’re using a new domain, a new IP, or a new vendor, or because your volume will increase—you should warm-up your domain and/or IP.
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.
Each sender has different constraints and needs, so these numbers are meant as
a baseline. Our Support team can work with you on
devising a plan adapted to your needs.
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
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 |