Email marketing is a powerful way to connect with your audience, but if you don't properly warm up your domain, you risk getting flagged as spam. Internet Service providers (ISPs) like Gmail, Yahoo, and Outlook closely monitor new senders, and a sudden spike in email volume can raise red flags, hurting your deliverability.
The good news? With the right approach, you can build a solid sender reputation and ensure your emails reach their intended audience.
In this blog, we'll break down why domain warming matters, who needs to do it, and best practices to follow.
Domain warming is the process of gradually increasing the volume of emails sent from a new domain or IP address over time. This helps establish credibility with ISPs, reducing the likelihood of emails being marked as spam. The goal is to build a positive sender reputation by demonstrating consistent and responsible sending practices.
During the warming-up period, senders begin by emailing their most engaged recipients in small batches. As engagement metrics remain healthy (such as open rates and click-through rates), the sending volume is gradually increased.
By taking a gradual approach, you signal to ISPs that you are a legitimate sender with valuable content, rather than a spammer. This helps you build a solid foundation for your email marketing campaigns, ensuring that your messages reach the intended inboxes.
Domain warming is the foundation of a successful email strategy. Without it, your emails may never reach their intended audience, leading to missed opportunities and wasted marketing efforts. Here’s why it’s essential:
If you are starting fresh with a new email domain or IP, warming it up is essential. This includes,
Additionally, anyone dramatically increasing their email volume should consider domain warming.
To ensure a successful warm-up process, start small by sending around 50-100 emails per day to your most engaged users, and gradually increase that number over a few weeks. Typically, a warm-up process takes 4-8 weeks, depending on your total list size.
Focus on sending emails to people who actually want them. Begin with your most engaged subscribers—the ones who open, click, and interact with your messages. Stick to a consistent schedule to build trust with ISPs, and set up proper email authentication (SPF, DKIM, and DMARC) to verify your legitimacy.
Keep an eye on key metrics like open rates, click-through rates, bounce rates, and spam complaints. If something looks off, slow down and make adjustments. Gradually expand your audience by adding new segments of your email list once your initial engaged audience is receiving your emails smoothly.
To learn more about improving your email marketing health, check out our guide on 26 Ways to Improve Your Marketing Email Health Score.
Finally, never buy email lists, as this can get you flagged as spam. Instead, grow your list organically through opt-ins and lead magnets.
If you’re not sure where to start, here’s a simple warm-up schedule you can follow:
Week 1: Send 50-100 emails per day to engaged users.
Week 2: Increase volume to 200-500 emails per day while monitoring engagement.
Week 3: Scale up to 1,000-2,000 emails per day, adding less active recipients.
Week 4: Continue increasing volume, tracking engagement, and making adjustments as needed.
Week 5+: Reach your full target volume while maintaining a strong reputation.
In the long run, neglecting domain warming can damage your sender reputation, making it difficult to reach your audience and achieve your marketing goals.
Warming up your domain isn’t just a technical step—it’s a crucial process that ensures your emails reach inboxes, not spam folders. By following a structured approach, you’ll build a trusted sender reputation, improve deliverability, and see better results from your email marketing efforts.
For more insights on creating effective email nurture campaigns, watch our Webinar: Proven Scalable Email Nurtures.
Anna Haugen is a Solutions Architect at accelant with nine years of experience in marketing and sales operations. She specializes in improving business processes, solving complex challenges with sustainable solutions, and leveraging new technologies to drive efficiency. Anna has managed MarTech stacks across various industries and company sizes, including supporting Amazon’s go-to-market for Buy with Prime and serving as a core administrator for the world’s largest Pardot instance (224M records) with Amazon Business. Outside of work, she is an avid long-distance runner and cross-country skier and can often be found hiking, camping, or exploring the mountains.