Summary
Migrating to a new Email Service Provider (ESP) requires a strategic, phased approach to safeguard sender reputation. The process centers on gradually warming up new IP addresses, rigorously cleaning subscriber lists, ensuring all domain authentication protocols are correctly configured, and continuously monitoring key deliverability metrics. Maintaining parallel operations with both the old and new ESPs for an extended period, avoiding any rush in the transition, is a widely recommended practice. This meticulous planning helps mitigate the risk of reputation loss and ensures consistent inbox placement.
Key findings
- IP Reputation Impact: A primary challenge when migrating ESPs is the potential loss of IP reputation due to new IP addresses. Google often prioritizes domain reputation, allowing for a slower IP phase-in if the sending domain remains consistent, while Microsoft heavily relies on smooth IP warm-up.
- ESP Onboarding Support: Reputable Email Service Providers are expected to provide dedicated support and a defined ramp-up plan as part of their onboarding process to facilitate a smooth and successful migration.
- Subdomain Strategy: The feasibility of using the same subdomain on both old and new systems concurrently depends on the new ESP's delegation process. If high performance has been achieved, it can be replicated with a new subdomain by migrating slowly and moving the most engaged recipients first.
- Benchmarking Performance: Benchmarking current engagement metrics by ISP before migration is crucial for establishing a baseline. This allows for effective measurement and comparison of performance during the transition to the new ESP.
- Common Pitfalls: Major pitfalls during ESP migration include failing to properly warm up new IPs, migrating uncleaned or disengaged lists, neglecting to set up proper email authentication, and not consistently monitoring sending metrics and recipient engagement.
Key considerations
- Gradual IP Warm-up: Implement a meticulous IP warm-up strategy by slowly increasing email volume, beginning with your most engaged subscribers and progressively expanding to less engaged segments to build a positive sending history with Internet Service Providers (ISPs).
- Thorough List Hygiene: Before migrating, rigorously clean your subscriber list by removing inactive or unengaged recipients. Sending only to a clean, active list on the new ESP is vital for maintaining sender reputation and ensuring better deliverability.
- Domain Authentication Setup: Ensure all necessary authentication protocols-SPF, DKIM, and DMARC-are correctly set up and authenticated on the new ESP before sending any emails, as these are fundamental for ISPs to trust your sending domain and maintain your sender reputation.
- Parallel System Operation: Run both the old and new email systems in parallel for as long as feasible, allowing for a gradual transition of sending volume and enabling direct comparison of deliverability metrics between platforms to identify any issues early.
- Continuous Monitoring: Throughout the migration, diligently monitor key sender reputation metrics, including inbox placement rates, bounce rates, spam complaints, and engagement (opens/clicks), via tools like Google Postmaster Tools or your new ESP's reporting to quickly address any issues.
- Subscriber Communication: Develop a clear communication plan to inform subscribers about the ESP migration, especially for transactional emails, to prevent confusion and minimize the risk of spam reports, thereby protecting sender reputation.
- Leverage ESP Support: Engage with your new ESP's deliverability team from the outset of your migration. Their expertise can help tailor the IP warm-up schedule and provide insights specific to your sending volume and list quality, which is crucial for maintaining reputation.
- Thorough Testing: Before full-scale deployment, thoroughly test your email campaigns on the new ESP. This includes rendering tests across various clients and devices, and sending test emails to different email providers to catch any deliverability issues early.
What email marketers say
11 marketer opinions
Successfully moving to a different Email Service Provider requires a well-orchestrated approach to preserve sender reputation. Key strategies involve a careful warm-up of new IP addresses, meticulous list hygiene, ensuring all domain authentication is flawlessly configured, and continuous performance monitoring. A gradual transition, potentially involving parallel operation of both platforms, is critical to avoid reputation setbacks and secure consistent inbox delivery.
Key opinions
- Differing ISP Priorities: Google prioritizes domain reputation, allowing a more gradual IP warm-up if the sending domain is consistent. Microsoft, conversely, places a strong emphasis on a smooth and prompt IP warm-up.
- ESP Onboarding Criticality: A reputable Email Service Provider will actively support migration with a defined ramp-up strategy during onboarding, which is crucial for minimizing disruption.
- Subdomain Parallelism: The feasibility of concurrently using the same subdomain on both old and new systems depends entirely on the new ESP's delegation capabilities. Successful replication of high performance often involves slowly migrating highly engaged users to a new subdomain.
- Pre-Migration Benchmarking: Measuring existing email performance metrics, particularly engagement rates by ISP, before migration establishes a vital baseline for evaluating the success of the transition.
- IP Reputation Regain Time: A common challenge during ESP migration is the considerable time required to re-establish IP reputation on new IP addresses, emphasizing the need for a careful warm-up.
Key considerations
- Aggressive List Hygiene: Prior to migration, thoroughly cleanse your subscriber list by removing all inactive or unengaged contacts. Sending only to a clean, active audience on the new platform is paramount for preserving sender reputation.
- Comprehensive Authentication: Ensure all essential email authentication protocols-SPF, DKIM, and DMARC-are accurately configured and verified on your new ESP before sending any emails. These protocols are fundamental for ISPs to trust your domain.
- Phased Volume Ramp-up: Implement a slow, controlled increase in sending volume on the new ESP, starting with your most engaged subscribers. This gradual approach is key to building a positive sending history with Internet Service Providers (ISPs).
- Proactive Subscriber Communication: Develop and execute a clear plan to inform subscribers about the ESP transition, especially for transactional communications. This helps prevent confusion, reduces spam complaints, and safeguards your sender reputation.
- Vigilant Performance Monitoring: Continuously track critical sender reputation metrics such as inbox placement, bounce rates, and complaint rates using tools like Google Postmaster Tools or your new ESP's reports. This allows for rapid issue identification and resolution.
- Pre-Launch Campaign Testing: Conduct exhaustive testing of your email campaigns on the new ESP before full deployment. Verify rendering across diverse email clients and devices, and send test emails to various providers to catch any deliverability issues early.
- Leverage ESP Expertise: Engage proactively with your new ESP's deliverability and onboarding teams. Their specialized guidance can help tailor your IP warm-up schedule and provide insights crucial for maintaining reputation during the move.
- Strategic Parallel Sending: If technically supported by the new ESP, consider running both your old and new systems in parallel for a period. This facilitates a smooth, gradual shift of sending volume and allows for direct comparison of performance.
Marketer view
Email marketer from Email Geeks explains that the most common pitfall when migrating to a new ESP is needing significant time to regain IP reputation due to new IP addresses. He notes that with Google, slowly phasing in new IPs while keeping the same sending domain may allow one to retain reputation, as Google predominantly focuses on the domain. For Microsoft, warming up new IPs smoothly is essential.
26 May 2022 - Email Geeks
Marketer view
Email marketer from Email Geeks shares that a reputable ESP will provide support and define a ramp-up plan during your onboarding process.
18 Dec 2023 - Email Geeks
What the experts say
4 expert opinions
Transitioning to a new Email Service Provider (ESP) while preserving sender reputation calls for a methodical and patient strategy. It involves running existing and new systems in tandem to allow for a measured warm-up of new IP addresses. Central to this process are also diligent list cleansing, comprehensive email authentication setup, and persistent monitoring of deliverability metrics. Avoiding hasty decisions and adhering to a detailed plan are paramount for a smooth shift without compromising inbox placement.
Key opinions
- Parallel System Benefits: Operating both old and new ESP systems concurrently for an extended period offers a safer transition and allows for cautious volume migration, which is particularly beneficial when utilizing dedicated IP addresses.
- Migration Checklist Importance: Successful ESP migration hinges on a comprehensive checklist that covers essential steps like proper IP warm-up, meticulous list hygiene, email authentication setup, and continuous performance monitoring.
- Patient IP Warm-up: A critical component for retaining sender reputation is a meticulous and unhurried IP warm-up process, involving a gradual increase in email volume to the most engaged segments, thereby building trust with Internet Service Providers (ISPs).
- Avoiding Pitfalls: Protecting sender reputation during an ESP migration necessitates actively steering clear of common errors, including insufficient IP warm-up, migrating disengaged lists, neglecting authentication, and failing to monitor metrics.
Key considerations
- Unrushed Warm-up Strategy: Implement an exceptionally patient and unhurried IP warm-up process, especially when using dedicated IP addresses, allowing ample time to establish a positive sending history and trust with ISPs.
- Strict List Cleanliness: Before migrating, rigorously clean your subscriber lists to ensure only active, engaged recipients are transferred, as sending to disengaged or uncleaned contacts can quickly damage new IP reputation.
- Comprehensive Migration Plan: Develop and adhere to a detailed migration checklist covering all technical and strategic aspects, from IP warm-up and authentication to list hygiene and ongoing performance monitoring, to ensure a smooth transition.
Expert view
Expert from Email Geeks advises running both the old and new email systems in parallel for as long as possible and emphasizes the importance of not rushing the warm-up process, especially if using dedicated IP addresses.
26 Sep 2021 - Email Geeks
Expert view
Expert from Spam Resource explains that successful ESP migration requires a comprehensive checklist to maintain sender reputation, including a proper IP warm-up, migrating only clean and engaged subscriber lists, setting up email authentication (SPF, DKIM, DMARC), and consistently monitoring engagement and deliverability metrics while gradually increasing email volume.
27 Aug 2022 - Spam Resource
What the documentation says
7 technical articles
Shifting to a different Email Service Provider demands a rigorous adherence to best practices to protect your sender reputation. This involves a strategic, phased approach, starting with a meticulous warm-up of new sending infrastructure and careful segmentation of your audience. Critical steps also include setting up robust domain authentication, maintaining an overlap period with your previous ESP, and closely monitoring performance metrics. Proactive engagement with your new ESP's deliverability experts is also essential for a seamless and reputation-safe transition.
Key findings
- Controlled Volume Increase: Gradually scaling email volume on new IP addresses, starting with highly engaged segments, is fundamental for building sender trust.
- Mandatory Authentication Setup: Correct configuration of SPF, DKIM, and DMARC on the new platform is a foundational prerequisite for maintaining domain trust and deliverability.
- Engagement-Led Migration: Prioritizing the migration of your most engaged subscribers first helps establish a positive sending reputation from the outset.
- Strategic Platform Overlap: Maintaining simultaneous operation of old and new ESPs provides a safer, more controlled transition and allows for performance comparison.
- Continuous Metric Oversight: Diligently monitoring metrics like bounce rates, spam complaints, and engagement is crucial for early detection and resolution of any reputation issues.
- Leveraging ESP Deliverability Teams: Collaborating closely with your new ESP's deliverability experts offers tailored guidance, optimizing the warm-up process for your specific sending profile.
Key considerations
- Systematic IP Warm-up: Initiate your migration by systematically warming up new IP addresses, gradually increasing sending volume and prioritizing highly engaged subscribers to build a strong reputation with Internet Service Providers, ISPs.
- Pre-Migration Authentication: Prior to sending any emails, ensure all critical domain authentication protocols-SPF, DKIM, and DMARC-are accurately set up and verified on your new Email Service Provider.
- Engagement-Based Volume Scaling: Segment your subscriber list and gradually transition segments, starting with your most active users on the new ESP, before progressively moving less engaged groups.
- Concurrent Platform Operation: Implement an overlap period where both your existing and new ESPs are active, allowing for a measured transition of email volume and enabling direct comparison of deliverability metrics.
- Proactive Metric Analysis: Establish a routine of continuously monitoring key deliverability metrics, including bounce rates, spam complaints, and engagement data, opens and clicks, to quickly identify and address any potential issues.
- Collaborate with ESP Experts: Actively engage with your new ESP's dedicated deliverability team. Their specialized knowledge can help tailor your IP warm-up strategy and provide crucial insights for maintaining your sender reputation.
- Maintain List Health: Consistently send to clean, engaged lists, even when migrating, as this practice is fundamental to preserving a positive sender reputation with major Internet Service Providers.
Technical article
Documentation from SendGrid explains that a crucial step in migrating ESPs is to gradually warm up new IP addresses by slowly increasing email volume, starting with highly engaged subscribers, and monitoring deliverability metrics closely to maintain sender reputation.
27 Jan 2022 - SendGrid
Technical article
Documentation from Iterable advises to segment your audience based on engagement, starting with the most active subscribers on the new ESP, while gradually moving less engaged segments, ensuring a slow and controlled volume increase to preserve sender reputation.
14 Jan 2024 - Iterable
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