> ## Documentation Index
> Fetch the complete documentation index at: https://help.privy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Warming Up a Custom Sending Domain

> Establish a good domain reputation and set your emails up for strong deliverability.

Warming up a sending domain is essential for ensuring high deliverability rates and maintaining a good sender reputation. This guide will walk you through the best practices for warming up a brand new domain and when switching between email service providers (ESPs).

## What is Domain Warming?

Warming up a sending domain involves gradually increasing the volume of emails sent from a new domain to build a positive sender reputation with Internet Service Providers (ISPs). This is crucial when starting with a new domain or even changing ESPs to avoid being flagged as spam.

## Preparing your domain

**If you're planning to use a brand new domain:**

* Set up your authentication records (DMARC, SPF, and DKIM).

* Verify your domain in your email service provider.

* Ensure your domain is clean and hasn’t been previously blacklisted.

**If you're using the same domain, but switching ESPs:**

* Verify DKIM, SPF, and DMARC records are updated to reflect the new ESP.

* Re-import and map all contact permissions accurately to the new system.

## The Warm Up Process

Warming up your sending domain will take at least 3 weeks. Here's the process we recommend:

**Week 1:**

* Send emails to your most engaged users (open rates > 30%).

* Limit volume to 50-100 emails per day.

**Week 2:**

* Gradually increase the volume by 100% daily, targeting engaged users.

* Monitor bounce rates and engagement closely.

**Week 3 and Beyond:**

* Continue to double the daily sending volume each week.

* Begin including less engaged users in small batches.

* Adjust the pace based on ISP feedback and engagement metrics.

## Best Practices

**Monitor Performance:**

* Use tools to track open rates, click-through rates, and bounces.

* Watch for any signs of being flagged as spam and adjust accordingly.

* Use the available Postmaster tools (i.e., Google and Yahoo) to monitor your domain’s health.

**Engage with Contacts:**

* Send personalized and relevant content.

* Promptly handle unsubscribe requests to maintain a clean list.

**Maintain List Hygiene:**

* Regularly update and clean your email list.

* Remove inactive contacts to improve engagement metrics.

**Compliance:**

* Ensure all contacts have explicitly opted-in to receive emails.

* Adhere to CAN-SPAM Act regulations and other relevant laws.

## Troubleshooting

**High Bounce Rates:**

* Review and improve email content and relevance.

* Verify email addresses and use [double opt-in](https://help.privy.com/docs/learn/contact-management/email-opt-in#double-opt-in) methods.

**Low Engagement:**

* [Segment](https://help.privy.com/docs/learn/email-campaigns/segmentation) your audience further for more targeted and personalized campaigns.

* Improve subject lines and email content to boost interest.

By following these steps and best practices, you can effectively warm up your sending domain, ensuring high deliverability and a strong sender reputation.