Summary
Changing email service providers (ESPs) and modifying your domain name significantly impacts your sender reputation and overall email deliverability. While your domain's reputation typically carries over, introducing changes to both your ESP and domain simultaneously can lead to short-term disruptions.
Key findings
- Immediate impact: Switching ESPs and changing domains introduces significant change, requiring mailbox providers to re-evaluate your sending practices.
- Domain reputation persistence: A domain's reputation is largely tied to its history and practices, which generally persists even if you switch ESPs. However, changing the domain itself means starting a new reputation for that specific domain.
- IP reputation reset: When moving to a new ESP, you will likely be sending from new IP addresses, which start with a neutral reputation and require a warming period.
- Combined changes amplify risk: Performing both an ESP migration and a domain change simultaneously increases the complexity and potential for deliverability challenges.
- Subdomain benefits: Using separate subdomains for different types of email (e.g., transactional versus marketing) can help isolate reputation issues. For instance, if your marketing emails encounter problems, your critical transactional emails may remain unaffected. Learn more about how parent domain reputation affects subdomain deliverability.
- Reputation portability: While domain reputation is tied to the domain itself, your new ESP's IP reputation also influences deliverability. A new IP needs IP warming to build its own positive sending history.
Key considerations
- Phased approach: Consider changing your ESP first, allowing a few months for stability, and then implementing the domain change. This reduces the number of variables impacting deliverability simultaneously.
- Maintaining consistency: If your current domain has a strong reputation, explore options to retain it, possibly by using a new subdomain for the return-path with the new ESP. This can help leverage existing trust with mailbox providers.
- Authentication setup: Ensure all email authentication protocols like SPF, DKIM, and DMARC are correctly configured for your new setup before migrating. Preemptive updates to DNS records can smooth the transition. For comprehensive guidance, consult the M3AAWG Best Practices for Sending Domains.
- Unsubscribe handling: If your old domain is used in the list-unsubscribe header, ensure your new setup can process these requests for a minimum of 30-60 days after the switch to honor subscriber preferences.
- Link tracking domains: Do not reuse existing link tracking subdomains when moving to a new ESP, as this can break old links, including unsubscribe links. Set up new, distinct subdomains for this purpose.
What email marketers say
Email marketers frequently discuss the challenges and strategies involved in changing ESPs and domains, acknowledging the inherent risks to sender reputation and deliverability. Their experiences highlight the importance of careful planning and understanding the nuances of how these changes are perceived by mailbox providers.
Key opinions
- Short-term impact: Many marketers agree that changing ESPs and domains will negatively affect deliverability in the short term, as filters need time to adjust.
- Benefit-driven change: It is crucial to assess if the benefits of a domain change outweigh the deliverability risks, especially if the current domain has a strong reputation. If there's no real benefit, keeping the existing domain is often preferred.
- Mitigation through warming: Marketers often plan to mitigate deliverability issues by implementing a new IP warming process with the new ESP to gradually build trust. For more on this, see how email reputation transfers during IP warming.
- Avoiding fixing problems: Switching domains will not fix underlying deliverability issues if poor sending practices continue. Reputation is tied to behavior, not just the name. Learn how email sending practices impact domain reputation.
- Subdomain strategy: Marketers frequently use subdomains to segment sending types (e.g., transactional, marketing) and manage their reputation independently, reducing the risk of a widespread negative impact on the main brand domain.
Key considerations
- Simultaneous changes: Some marketers advocate for making all necessary changes (ESP and domain) at once to condense the painful period into a shorter, more intense transition.
- Gradual transition: A blended transition, where the old ESP continues to operate for a period while the new ESP is gradually ramped up, is often preferred for smoother deliverability and handling of existing unsubscribes. This is covered in best practices for migrating to a new ESP.
- Engagement first: During a transition, sending to the most engaged recipients first in smaller batches and slowly increasing volume can help build a positive reputation quickly with the new setup.
- Email list hygiene: Verifying older email addresses and cleaning inactive subscribers can significantly improve deliverability when migrating, as it reduces bounce rates and spam complaints.
- IT team coordination: Effective communication with your IT team is vital to ensure correct DNS record updates, SPF, DKIM, and DMARC configurations, which are critical for smooth transitions. Read more about how email sender reputation affects deliverability.
Marketer view
Email marketer from Email Geeks states that changing ESPs will introduce change, and filters take time to react. Changing the domain at the same time will only increase the degree of change, prolonging the time filters need to reacquaint themselves with the sender.
Marketer view
Email marketer from Email Geeks notes that if the domain is connected to a specific ESP (e.g., Dot Digital for return path), using it simultaneously with another provider might cause problems. Definitive answers require specific details on sending infrastructure.
What the experts say
Industry experts provide invaluable insights into the complexities of changing ESPs and domains, offering strategic advice to minimize deliverability risks and optimize sender reputation. Their perspectives often delve into the technical underpinnings and long-term implications of such transitions.
Key opinions
- Gradual transition advocated: Experts generally advise a gradual transition to a new ESP, especially if the domain reputation is strong. This allows for new IP warming while maintaining sending from the old platform.
- Domain vs. IP reputation: While domain reputation persists, IP reputation is reset with a new ESP. Both are crucial, and a new IP requires careful warming to establish trust with mailbox providers. Learn more about how sending domain, IP, and content affect reputation.
- Return-path focus: The return-path domain, especially if it has MX records tied to an ESP, is critical. Using a new subdomain for the return-path with the new vendor is often recommended for smoother transitions.
- Separation of sending types: It is best practice to separate subdomains based on purpose (e.g., transactional, marketing) to contain any potential deliverability issues to a specific sending stream, protecting the overall brand reputation.
- Avoid cousin domains: Experts strongly advise against using completely separate, unlinked cousin domains for sending, as this can make brand impersonation easier and irritate mailbox providers.
Key considerations
- Strategic timing: If a hard cut is necessary, ensure all existing automated campaigns are completed before making changes to MX records. This prevents loss of bounces and other critical mail stream data.
- Authentication preparedness: Preemptively updating SPF records and setting up DKIM (with different selectors) can help ensure a smooth authentication transition. This is crucial for maintaining trust with ISPs. Explore our guide on DMARC, SPF, and DKIM.
- Link domain stability: Avoid changing subdomains used for link tracking, as this can break old links, including unsubscribe links, which are legally required to function for a minimum period (30-60 days).
- Consulting ESPs: Always engage with your new ESP to understand their migration processes and recommendations. Their expertise is vital for a successful transition. For related advice, see building your sending reputation on a new ESP.
- Protecting the brand: In cases where a company insists on engaging in cold outreach (spam), experts suggest isolating these activities to a separate domain to prevent damage to the core brand's deliverability for opt-in mail.
Expert view
Email expert from Email Geeks notes that changing ESPs introduces change, and filters need time to react. Adding a domain change simultaneously increases the degree of change, extending the time filters take to reacquaint themselves with your sending.
Expert view
Email expert from Email Geeks suggests that if you are changing providers to fix a problem, changing your domain will not necessarily provide a long-term solution. If you have a strong domain reputation, consider keeping the domain and adding a new subdomain for the return path.
What the documentation says
Official documentation and research often provide foundational knowledge on how sender reputation and deliverability are affected by ESP and domain changes. These sources typically detail the mechanisms ISPs use to evaluate incoming mail and the best practices for maintaining a healthy sending posture.
Key findings
- Domain reputation fundamentals: Domain reputation is a core factor influencing deliverability, assessed by ISPs based on sending history, engagement metrics, and complaint rates associated with that domain. Learn how to improve domain reputation using Google Postmaster Tools.
- Shared vs. dedicated domains: Branded (dedicated) sending domains offer more control over sender reputation compared to shared domains, as the reputation is built solely on your sending behavior.
- DMARC and reputation: A strong DMARC implementation signals authenticity and helps build a robust sender reputation, leading to better email delivery rates. Refer to our list of DMARC tags and their meanings for technical details.
- Blacklist impact: If a domain (or even a subdomain) is listed on a blacklist or blocklist, it can severely impede email deliverability across the entire organizational domain. Monitor your domain with a blocklist checker.
- Subdomain independence (limited): While subdomains can offer some isolation, poor practices on a subdomain can still negatively reflect on the parent domain's reputation, particularly with more aggressive filtering policies.
Key considerations
- Consistent sending: Building a reliable sending reputation on a new ESP and/or domain requires consistent, compliant sending practices over time. This includes adhering to permission-based marketing and proper list management.
- Authentication alignment: Ensuring SPF, DKIM, and DMARC alignment for all sending domains and subdomains is paramount. Misconfigurations can lead to emails being flagged as suspicious or spam. Our DMARC record generator can assist with this.
- Impact of cousin domains: Some documentation suggests that using unrelated cousin domains for sending can be detrimental, as it might confuse recipients and increase phishing risks, ultimately impacting the brand's perceived legitimacy.
- Monitoring: Continuous monitoring of sender reputation, bounce rates, and complaint rates via tools like Google Postmaster Tools is essential to identify and address issues swiftly. This is vital for maintaining good email deliverability and improving sender domain reputation.
Technical article
Documentation from EmailLabs emphasizes that consistently high bounce rates can lead to ISPs throttling or blocking email delivery from a sender's domain, which directly harms the sender's reputation and deliverability.
Technical article
Klaviyo Help Center documentation clarifies that branded sending domains (also known as dedicated sending domains) provide greater control over your sender reputation, as they are solely associated with your sending practices, unlike shared domains.
Related resources
15 resources
Related pages
What are the best practices for migrating to a new ESP while retaining sender reputation?
How does email reputation transfer during IP warming with a new ESP, and how to resolve deliverability issues?
How do SPF, DKIM, DMARC, and dedicated IPs affect email deliverability when using a third-party ESP?
How do email sending practices impact domain reputation and deliverability?
How do multiple domain reputations affect email deliverability, and how can I improve my Google email reputation after sending spam?
How does parent domain reputation affect subdomain deliverability and sender reputation?
How does a domain change affect email deliverability and what steps should be taken to prevent issues like Gmail warnings?
How do spam reports affect email domain reputation and deliverability?
What happens when your domain is on an email blacklist?
How to improve domain reputation using Google Postmaster Tools [2025 guide]
