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).

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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.

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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.

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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.

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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.

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Troubleshooting

High Bounce Rates:

  • Review and improve email content and relevance.

  • Verify email addresses and use double opt-in methods.

Low Engagement:

  • Segment 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.