How do I transition to a new ESP while maintaining sends on my current platform using the same domain?

Summary

Transitioning to a new ESP while maintaining sends on your current platform and using the same domain requires a strategic and phased approach. A consensus emerges on the importance of using separate subdomains for each ESP, specifically for the envelope 'from' or bounce domain, to ensure proper bounce handling and SPF alignment. Unique DNS records, particularly SPF and DKIM, are essential for each ESP's subdomain. Experts emphasize the need for gradual IP warm-up, starting with small segments of engaged subscribers and closely monitoring key metrics like open rates, bounce rates, and spam complaints. Maintaining synchronized lists, running ESPs in parallel, A/B testing campaigns, and establishing feedback loops with email providers are also critical. Finally, proper configuration of SPF, DKIM, and DMARC records and consistently alerting email providers help ensure ongoing deliverability.

Key findings

  • Subdomain Isolation: Using different subdomains for the envelope 'from' address (bounce domain) is essential for proper bounce handling and SPF alignment with multiple ESPs.
  • Unique DNS Records: Each ESP requires its own SPF and DKIM records, configured for its corresponding subdomain.
  • Gradual IP Warm-up: A phased IP warm-up process, starting with small, engaged segments, is crucial for building a positive sender reputation.
  • Synchronized Lists: Maintaining synchronized lists across both ESPs, especially suppression lists, is critical to avoid deliverability issues and legal complications.
  • Importance of Monitoring: Continuous monitoring of key metrics (open rates, click-through rates, bounce rates, spam complaints) is essential for identifying and addressing deliverability problems.
  • SPF Configuration: SPF records should include the appropriate 'include:' statements for each ESP to ensure proper authentication.

Key considerations

  • Visible 'From' Address: While different subdomains are needed for the envelope 'from,' the same domain or subdomain can generally be used in the visible 'from' address.
  • Parallel Sending: Running both ESPs in parallel allows for comparison of performance and a gradual transition of email volume.
  • A/B Testing: A/B testing campaigns across both ESPs can identify any performance differences and help optimize the transition.
  • Feedback Loops: Establishing feedback loops with email providers is essential for monitoring and addressing deliverability issues.
  • Domain Reputation: Proactively manage and monitor your domain reputation, especially with key mailbox providers like Gmail, using tools like Google Postmaster Tools.
  • DNS Propagation: Allow enough time for changes in DNS records to fully propagate before launching large email sends.
  • Notify Providers: Alerting email providers with who you're now working with (new ESP) makes sure their systems get the right message about a new surge of emails from your company, as they're now using a different ESP.

What email marketers say
8Marketer opinions

Transitioning to a new ESP while maintaining sends on your current platform requires a strategic approach to avoid deliverability issues. Key steps include using different subdomains for the new ESP to prevent DNS conflicts, gradually warming up the new domain, replicating suppression lists across both ESPs, and closely monitoring performance metrics. Running ESPs in parallel, synchronizing lists, and A/B testing campaigns can provide valuable insights. Ensuring proper SPF record configurations with include statements for each ESP is also crucial.

Key opinions

  • Subdomain Isolation: Utilize different subdomains for the new ESP to avoid DNS conflicts and allow for gradual warm-up without impacting the primary domain's reputation.
  • Gradual Warm-Up: Gradually warm up the new domain by starting with low volumes and increasing sends over time to build a positive sender reputation.
  • List Replication: Replicate suppression lists across both ESPs to avoid sending to unsubscribed users during the transition.
  • Parallel Sending: Run both ESPs in parallel, splitting the email list to compare performance and gradually shift traffic to the new ESP.
  • SPF Records: Configure SPF records with include statements for each ESP to ensure proper authentication and prevent deliverability issues.

Key considerations

  • Monitor Metrics: Closely monitor key metrics such as open rates, click-through rates, and bounce rates on both ESPs to identify and address any deliverability issues.
  • Synchronize Lists: Maintain synchronized lists to ensure that unsubscribe requests are promptly reflected across both ESPs.
  • A/B Testing: A/B test email campaigns on both ESPs to identify performance differences and optimize results.
  • Reputation Management: Be aware of the domain and ip reputation on both services.
Marketer view

Email marketer from StackOverflow emphasizes the importance of using include: statements in the SPF records as each ESP will have a different authentication domain. This will help email services identify your company's domain.

January 2022 - StackOverflow
Marketer view

Email marketer from Email on Acid emphasizes maintaining synchronized lists. Ensure that unsubscribe requests are promptly reflected across both ESPs. Failing to do so may hurt your reputation and cause legal issues.

March 2023 - Email on Acid
Marketer view

Email marketer from Email Vendor Selection blog advises running both ESPs in parallel for a while. Split your email list and send a portion through the old ESP and the rest through the new one. Monitor results from each ESP to find out if the new one is up to par. Make a full switch only once you have enough confidence.

September 2024 - Email Vendor Selection
Marketer view

Email marketer from Campaign Monitor recommends A/B testing your email campaigns on both ESPs to identify any performance differences. Test different subject lines, content, and sending times to optimize your results and ensure a smooth transition.

July 2022 - Campaign Monitor
Marketer view

Email marketer from Quora answers to start by migrating a small segment of your audience to the new ESP, monitor performance, and gradually increase the volume as you gain confidence. Make sure to replicate your suppression lists in both ESPs to avoid sending to unsubscribed users during the transition.

December 2023 - Quora
Marketer view

Email marketer from Email Marketing Forum explains to transition gradually. Start by sending low-priority emails from the new ESP while continuing to send your main campaigns from the old one. This helps you build a sender reputation on the new platform without risking deliverability for critical emails. Monitor bounce rates and feedback loops closely.

July 2021 - Email Marketing Forum
Marketer view

Email marketer from Reddit user EmailPro shares that you should utilize different subdomains for your new ESP during the transition. This avoids DNS conflicts and allows for gradual warming up of the new domain while keeping your primary domain active on your old ESP. Once the new subdomain's reputation is strong, you can consider fully switching over or using both ESPs in parallel.

February 2024 - Reddit
Marketer view

Email marketer from Litmus shares to closely monitor your key metrics such as open rates, click-through rates, and bounce rates on both ESPs. Pay special attention to any deliverability issues, such as emails landing in the spam folder. Use this data to adjust your sending strategy and optimize your email content.

March 2023 - Litmus

What the experts say
8Expert opinions

Transitioning to a new Email Service Provider (ESP) while maintaining sends on your current platform, using the same domain, requires careful management of subdomains, SPF records, and IP warm-up. Experts recommend using the same domain/subdomain in the visible 'from' address but different subdomains in the envelope 'from' address to ensure proper bounce handling by each ESP. Each ESP should have its own SPF record, reflecting its unique bounce domain. A phased approach to IP warm-up is crucial, especially without dedicated IPs, involving small batches of recipients and close monitoring of performance metrics. It's important to establish feedback loops with email providers and ensure DNS records are accurate.

Key opinions

  • Subdomain Differentiation: Use different subdomains for the envelope 'from' address (bounce domain) for each ESP to enable correct bounce processing.
  • SPF Records per ESP: Each ESP must have its own SPF record, aligning with its unique bounce domain (e.g., esp1.domain.com).
  • IP Warm-up: Handle IP address warm-up gradually, especially without dedicated IPs, by sending to small batches of recipients and monitoring performance.
  • Visible From Address: The same domain or subdomain can be used in the visible 'from' address across ESPs.
  • DKIM Subdomains: Using different subdomains in the d= for DKIM is recommended.

Key considerations

  • DNS Records: Ensure all DNS records (SPF, DKIM, DMARC) are correctly configured for each ESP and subdomain.
  • Feedback Loops: Enable feedback loops with email providers to monitor and address deliverability issues.
  • Performance Metrics: Closely monitor performance metrics like bounce rates and spam complaints during the transition.
  • Consistent Sending: Maintain consistent sending practices to preserve reputation.
  • SPF Alignment: Ensure that the SPF record aligns with the bounce domain to maintain deliverability.
Expert view

Expert from Email Geeks defines SPF Domain as the Envelope From / Return Path / Bounce domain / 5321.from. The end user does not see this domain unless they go look for it. It is the domain that is checked by SPF and the one that must match the Visible From domain for DMARC to pass. It does not need to be a domain controlled by the sending entity. Defines Visible From domain as what most non-email-geek people think of as the From domain. This is what is visible to the end user when they read their mail (assuming their mail client doesn’t hide it like all too many of them do). This is what consumer filters use to help drive delivery to individual user inboxes. This is the domain that is verified by DMARC.

March 2024 - Email Geeks
Expert view

Expert from Word to the Wise recommends using different subdomains for the envelope from address (the bounce domain) when using multiple ESPs simultaneously. This ensures that each ESP can handle bounces correctly and maintains proper SPF alignment. You can, however, use the same subdomain in the visible from address.

March 2023 - Word to the Wise
Expert view

Expert from Email Geeks explains to use the same domain/subdomain in the visible from address and collect any direct responses directly.

October 2022 - Email Geeks
Expert view

Expert from Word to the Wise responds that when migrating from one ESP to another, it's essential to handle IP address warm-up with care, especially if you are not using dedicated IPs. Use a phased approach, moving small batches of recipients to the new ESP over time and closely monitor performance metrics such as bounce rates and spam complaints. Maintain proper authentication and list hygiene throughout the transition to avoid deliverability issues.

February 2023 - Word to the Wise
Expert view

Expert from Email Geeks shares an example of in your case, the SPF domain might be <http://esp1.bounce.wttwmail.com|esp1.bounce.wttwmail.com> for ESP1 and <http://esp2.bounce.wordtothewise.com|esp2.bounce.wordtothewise.com> for ESP 2

July 2022 - Email Geeks
Expert view

Expert from Word to the Wise responds that when changing ESPs to make sure you let the email providers know. Do this by enabling the feedback loop with the new ESP and make sure you are sending consistently. Finally ensure your DNS records are all correct.

August 2024 - Word to the Wise
Expert view

Expert from Email Geeks shares that each ESP should have its own SPF record (e.g., esp1.domain.here v=spf1 include:_spf.esp1.here) because the envelope from is unique to each ESP, you can have a single SPF record for each subdomain.

July 2024 - Email Geeks
Expert view

Expert from Email Geeks explains that you must have different subdomains in the envelope from address so that each ESP can bounce handle mail correctly but you can have the same subdomains in the visible from address and recommends different subdomains in the d= for DKIM.

May 2022 - Email Geeks

What the documentation says
5Technical articles

Transitioning to a new ESP while maintaining sends on an existing platform and domain requires careful planning, particularly around DNS configuration, IP warming, and reputation management. Key recommendations from documentation include setting up separate subdomains for each ESP, ensuring unique SPF and DKIM records, and gradually warming up the new IP address by sending to engaged subscribers. Monitoring sender reputation and engagement metrics is crucial, as is ensuring proper configuration of SPF, DKIM, and DMARC records to maintain deliverability, especially with Gmail.

Key findings

  • Subdomain Isolation: Separate subdomains for each ESP are recommended to avoid DNS conflicts and maintain distinct authentication settings.
  • Unique DNS Records: Each ESP needs unique DNS records, particularly SPF and DKIM, configured for its respective subdomain.
  • IP Warmup is Essential: Gradually warm up the new IP address and domain by starting with low volumes sent to highly engaged subscribers.
  • Sender Reputation Matters: Maintaining a positive sender reputation is crucial for email deliverability, especially with mailbox providers like Gmail.
  • Authentication Configuration: Proper configuration of SPF, DKIM, and DMARC records is essential for all sending domains and subdomains.

Key considerations

  • Monitoring: Continuously monitor sender reputation and engagement metrics to identify and address deliverability issues.
  • Feedback Loops: Set up and monitor feedback loops to understand how mailbox providers are viewing your email traffic.
  • Engagement: Focus on sending to engaged subscribers during the IP warmup process to establish a positive sending reputation.
  • DNS Propagation: Allow sufficient time for DNS record changes to propagate fully before initiating significant email volume from the new ESP.
  • Google Postmaster Tools: Utilize Google Postmaster Tools to monitor domain and IP reputation specifically for Gmail users.
Technical article

Documentation from SendGrid emphasizes the importance of IP warmup. Start by sending low volumes of emails to your most engaged subscribers and gradually increase the volume over time. This helps build a positive sender reputation with mailbox providers.

July 2022 - SendGrid
Technical article

Documentation from Amazon Web Services suggests setting up separate subdomains for each ESP you intend to use. This allows you to maintain separate SPF and DKIM records for each, avoiding conflicts and ensuring proper authentication. Each subdomain should handle its own bounces and feedback loops.

September 2024 - Amazon Web Services
Technical article

Documentation from SparkPost advises creating unique DNS records for each ESP, particularly SPF and DKIM records. Use a subdomain for the new ESP to prevent conflicts with your existing domain's authentication settings. Also mentions setting up dedicated IP addresses for each ESP.

July 2023 - SparkPost
Technical article

Documentation from Mailjet recommends warming up your new IP address and domain gradually by starting with low volumes and increasing over time. Monitor your sender reputation and engagement metrics to ensure deliverability.

June 2024 - Mailjet
Technical article

Documentation from Google Workspace explains that domain reputation plays a critical role in email deliverability, especially with Gmail. Ensure you have properly configured SPF, DKIM, and DMARC records for all sending domains and subdomains. Monitor your sender reputation using Google Postmaster Tools to identify and address any deliverability issues.

June 2022 - Google