What are the best practices for switching to a new sending domain?

Key findings

• New domain status: ISPs treat a new sending domain as if it has no sender history, regardless of whether the IP address remains the same. This means you start with a neutral reputation, which requires building trust.
• Warm-up essential: A gradual warm-up process is critical for the new domain, involving slowly increasing sending volumes to establish a positive sender reputation and avoid blocklists (also known as blacklists). This applies to all aspects of the domain, including the 'From' address, return path, DKIM signature, and links within the email.
• Avoid simultaneous changes: It is highly recommended to avoid changing your sending IP address at the same time as your domain, as this compounds the reputation challenge and makes it harder to diagnose deliverability issues.
• Comprehensive updates: All technical configurations, including SPF, DKIM, and DMARC records, must be correctly set up for the new domain to ensure proper authentication and alignment.

Key considerations

• Gradual ramp-up: Implement a careful, staged migration, starting with low volumes to highly engaged segments and slowly increasing over time. This helps ISPs build trust in your new domain.
• DNS configuration: Ensure all necessary DNS records for your new domain are correctly configured with your DNS provider. This includes not just SPF, DKIM, and DMARC, but also potentially a new return-path domain if you're changing ESPs or setting up subdomains.
• Subscriber notification: Inform your subscribers about the domain change in advance to prevent confusion and reduce spam complaints. This proactive communication can help maintain positive engagement and reduce the risk of your messages being marked as spam.
• Consistent branding: Maintain consistent branding and messaging across all email elements to reinforce the new domain's legitimacy. Avoid creating cousin domains (e.g., example-deals.com) that might look like phishing attempts.
• Monitor deliverability: Continuously monitor your email deliverability and domain reputation using tools like Google Postmaster Tools and other analytics. Pay close attention to bounces, spam complaints, and inbox placement rates to quickly identify and address any issues. For more details on this, you can review our guide on understanding your email domain reputation.

Key opinions

• Reputation reset: Many marketers view a domain switch as a complete reset of their sending reputation with ISPs. It means starting from scratch to build trust, similar to warming up a new IP.
• Gradual migration: The consensus is to gradually introduce the new domain, especially for transactional and marketing emails, to avoid sudden drops in deliverability. This could involve segmenting audiences and migrating them in phases.
• Subscriber communication: Informing subscribers about the domain change is a critical step to prevent confusion, reduce unsubscribes, and minimize spam complaints, which can negatively impact the new domain's reputation.
• Subdomain strategy: Some marketers advocate for using subdomains to separate different types of email sends (e.g., transactional, marketing, support) to isolate potential deliverability issues and manage sender reputation more effectively.

Key considerations

• Technical setup: Marketers need to work closely with their technical teams or ESPs to ensure proper setup of DNS records, including SPF, DKIM, and DMARC, for the new domain. Errors here can lead to authentication failures.
• Email content adjustments: Reviewing and updating all links, images, and branding within email templates to reflect the new domain is essential. Broken links or outdated branding can erode trust.
• Engagement monitoring: Closely tracking engagement metrics (opens, clicks, unsubscribes, complaints) for emails sent from the new domain is vital. Early detection of drops in engagement can signal deliverability issues.
• Long-term strategy: Consider the long-term impact on sender identity and brand recognition. For guidance on consistent sender identity, refer to our page on best practices for consistent newsletter sender identity. It's also worth reviewing what email adjustments are needed if you change email domains, according to Inbox Collective.

Key opinions

• New domain, new reputation: Experts consistently highlight that a new domain is perceived as completely new by ISPs, carrying no pre-existing reputation. This necessitates a strategic build-up of trust.
• Warm-up imperative: The warm-up process for a new domain is as critical as that for a new IP. Gradual volume increases, starting with engaged users, are essential to build a positive sending history.
• Avoid combined changes: It's strongly advised to avoid switching both the IP and the domain simultaneously, as this introduces too many variables and makes troubleshooting deliverability issues exceedingly difficult.
• Holistic domain impact: The domain's reputation affects all associated components: the 'From' address, return path, DKIM signing domain, and click-tracking links. All must be carefully migrated and warmed up.

Key considerations

• Phased rollout: Experts recommend not switching all email streams or segments to the new domain at once. A phased rollout allows for monitoring and adjustments without risking all traffic.
• Authentication configuration: Proper configuration of SPF, DKIM, and DMARC for the new domain is paramount. Misconfigurations are a common cause of deliverability failures. Learn more about authentication best practices.
• Sender reputation awareness: A deep understanding of how email sending practices impact domain reputation is critical. Any issues, such as high spam complaints or bounces, will disproportionately affect a new domain.
• Monitoring tools: Leverage tools like Google Postmaster Tools and commercial deliverability platforms to monitor the new domain's performance. Early detection of issues allows for quicker intervention.

Key findings

• Authentication protocols: Documentation consistently emphasizes the critical role of SPF, DKIM, and DMARC in authenticating sending domains. For a new domain, these records must be correctly configured and aligned.
• Reputation building: Mailbox providers expect new domains to establish a sending history through a controlled warm-up process, gradually increasing volume and maintaining high engagement to build trust.
• Subdomain utilization: Best practices often recommend using subdomains for different email types (e.g., transactional vs. marketing) to compartmentalize sender reputation and minimize risk across diverse sending streams.
• Compliance with sender requirements: Major providers like Microsoft and Google have specific sender requirements for high-volume senders, including strong authentication, low spam rates, and easy unsubscribe options. A new domain must comply from the outset.

Key considerations

• DNS record updates: All DNS records, including MX, SPF, DKIM, and DMARC, must be updated and propagated correctly for the new domain. Incomplete or incorrect records can lead to delivery failures.
• Consistent sending practices: Maintain consistent sending practices, including list hygiene, engagement monitoring, and prompt handling of complaints, to build a positive reputation quickly on the new domain. Find out more about choosing an email sending domain.
• Monitoring tools: Utilize Postmaster Tools (e.g., from Google and Microsoft) to track domain reputation, complaint rates, and authentication status. This data is invaluable for course correction during a domain switch.
• Domain reputation and IP impact: While IP reputation is distinct, a poor domain reputation can negatively impact it, and vice-versa. Understanding the interplay is crucial for deliverability. Our guide on IP and domain warm-up strategies provides further insight.