What steps should I take to resolve deliverability issues after rebranding with a new domain and ESP?

Key findings

• Simultaneous changes: Changing both your domain and ESP at the same time poses a significant challenge, making it difficult to isolate the cause of deliverability issues.
• Reputation is key: New domains and IP addresses lack established sender reputation, causing mailbox providers to treat initial email volumes as suspicious. This leads to emails being flagged as spam, even for legitimate senders, due to the absence of positive sending history. Learn more about how email reputation transfers.
• Warmup necessity: A proper domain and IP warming process is crucial to build sender reputation and ensure consistent inbox placement. Neglecting this step often results in poor performance.
• Authentication validation: Even with correct SPF, DKIM, and DMARC records, misconfigurations or strict DMARC policies (like p=quarantine) can lead to emails being sent to spam if alignment is not perfectly maintained. It is important to know the basics of DMARC, SPF, and DKIM.
• Blocklists often not the primary issue: While blocklist (or blacklist) presence can contribute, it is usually not the root cause of widespread spam placement after a major migration, especially on less commonly used blocklists. High bounce rates explicitly mentioning blocklists would indicate this as the main issue.

Key considerations

• Strategic sender communication: Inform your subscribers about brand and domain changes from your established, trusted domain before transitioning. This helps manage recipient expectations and reduces spam complaints from unfamiliar senders. Consider this helpful guide on domain changes.
• Phased domain warmup: Implement a gradual domain warming strategy for the new domain. Start with small batches of highly engaged users and slowly increase volume, allowing mailbox providers to assess your sending behavior and build a positive reputation over time. This is critical for best practices when switching domains.
• Authentication audit: Thoroughly review and confirm all authentication records (SPF, DKIM, DMARC) for the new domain and ESP configuration. Ensure DMARC alignment is consistently passing, especially with a p=quarantine or p=reject policy. Any misstep can severely impact deliverability.
• List hygiene: Clean your email lists before migrating to a new ESP and domain. Remove unengaged subscribers, invalid addresses, and known spam traps. Sending to a clean list during warmup improves positive engagement signals.
• Monitor and adapt: Continuously monitor your deliverability metrics (open rates, click-through rates, bounces, complaints) and adjust your sending strategy as needed. Low open rates, even for test sends to your own inboxes, are strong indicators of a reputation or configuration issue.

Key opinions

• Rebranding complexity: Marketers find that a major rebranding, especially with a new domain and multiple ESP changes, complicates deliverability significantly. The scale of the change often prevents last-minute adjustments to a more gradual migration plan.
• Immediate spam folder placement: Initial sends from a new domain or ESP are frequently directed straight to the spam folder, leading to very low open and click-through rates, regardless of previous sender history with the old setup. Reputation repair is critical.
• Misinterpretation of blocklists: There's a common misconception that minor blocklist (or blacklist) entries are the primary cause of widespread spam issues, when in reality, they often have limited impact on overall inbox placement for major mailbox providers.
• Challenges with data migration: Marketers frequently encounter difficulties with timely and accurate data exports and imports between different ESPs, sometimes forcing them to revert to older, less suitable platforms for urgent campaigns.
• Desire for quick fixes: Many marketers seek immediate solutions like quick list cleanups or blacklist removal requests, sometimes overlooking the fundamental need for a systematic warmup process.

Key considerations

• Prioritize domain warmup: Despite organizational pressures, a gradual domain warmup is paramount. Rushing sends from a new domain, even if it's technically not a newly registered one, will likely result in poor deliverability.
• Communicate brand change proactively: Send an introductory campaign from the old, trusted domain to announce the rebrand and new sending domain. This helps subscribers recognize the new sender and reduces spam complaints. This is part of a comprehensive migration checklist.
• Verify authentication thoroughly: Ensure that SPF, DKIM, and DMARC are correctly implemented and passing for the new domain and ESPs. Any authentication failures, especially with a DMARC p=quarantine policy, will push emails to spam.
• Focus on engagement for warming: During the warmup period, send emails to your most engaged segments first. Positive engagement signals (opens, clicks, replies, not marking as spam) are vital for building a strong sender reputation.
• Strategic sending schedule: Throttle sends and use smaller batches from the new domain, gradually increasing volume. This mimics organic sending behavior and helps mailbox providers trust your new setup.

Key opinions

• Domain warmup is paramount: Experts agree that the most probable cause of deliverability issues after a simultaneous domain and ESP change is insufficient domain warming. Mailbox providers default to classifying mail from new, high-volume setups as spam until a positive reputation is built.
• Blocklists are rarely the main problem: Minor blocklist (or blacklist) listings on less common lists (e.g., NoSolicitado, Hostkarma) are typically not the primary driver of widespread spam folder delivery. Significant blocklisting would manifest as high bounce rates with explicit blocklist mentions.
• Recipient recognition impacts reputation: When a company changes its name and sending domain, recipients may not recognize the sender, leading to spam reports or disengagement. This negative feedback severely harms the new domain's reputation. This aligns with advice on sending from a new domain for an existing company.
• Authentication is critical: Even with an old domain, if SPF, DKIM, and DMARC authentication (especially with a p=quarantine policy) are not 100% correct, emails are likely to land in spam. This ensures boosted email deliverability.
• Domain age not always a factor: While newly registered domains (under 6 months) can face deliverability challenges, older domains undergoing rebranding still require warming. It's the new sending reputation for that specific domain-ESP combination that matters.

Key considerations

• Systematic warmup strategy: Develop and execute a careful domain warmup plan. This involves starting with your most engaged subscribers, gradually increasing volume, and monitoring engagement to build positive signals with mailbox providers. This will help improve email IP and domain reputation.
• Proactive recipient education: Before transitioning, inform your audience about the brand and domain change using your existing, trusted sending domain. This prepares them for mail from the new domain, reducing the likelihood of spam complaints and disengagement, which can severely damage sender reputation.
• Deep dive into authentication: Verify every aspect of your authentication setup for the new ESP and domain. Ensure your custom return path is SPF authenticated, and you are signing with a custom DKIM key that aligns with your DMARC policy. This is especially crucial if you have a DMARC policy of p=quarantine.
• Monitor inbox placement: Actively test and monitor where your emails land across major mailbox providers (Gmail, Outlook, etc.). If emails are consistently going to spam, it's a clear indicator of a reputation issue that needs immediate attention, potentially indicating harder deliverability issues to solve.
• Patience and consistency: Recovering or building domain reputation is not an overnight process. It often takes a month or more of consistent, good sending practices to stabilize deliverability after significant changes.

Key findings

• Subdomain and DNS management: Documentation often advises ensuring that branded sending subdomains are not already in use within your DNS before migration. Proper DNS configuration, including MX records, is fundamental for email routing and deliverability.
• IP and domain warming guidelines: Official guides provide structured approaches to IP and domain warming, recognizing that reputation is tied to these assets and needs to be slowly built. This involves gradually increasing sending volume to establish trust with mailbox providers.
• Authentication setup: Detailed instructions are provided for setting up SPF, DKIM, and DMARC records to ensure proper email authentication. Misconfigurations or delays in DNS propagation (up to 24 hours) can lead to authentication failures and spam placement. This is key to fixing emails going to spam.
• Anticipate temporary dips: It's a common understanding that deliverability metrics might experience a temporary decline during the transition period to a new ESP or domain, which should be anticipated and managed.

Key considerations

• Pre-migration checklist: Many documentation sources offer comprehensive checklists for migrating ESPs, covering everything from DNS setup to subscriber communication, aiming to minimize deliverability impact. This includes knowing best practices for ESP migration.
• Subscriber notification: Proactive communication with subscribers about domain changes is advised. The sooner they are informed, the better, as it helps prevent confusion and potential spam reports when emails arrive from a new sender identity.
• Monitoring and testing: Regularly testing email content, formatting, and authentication helps identify potential spam triggers. Many ESPs offer tools for this, crucial for diagnosing deliverability drops after ESP migration.
• Consistency with authentication: Ensure that your SPF and DKIM authentication are properly configured and aligned with your sending domain to pass DMARC. A consistent and valid authentication setup is foundational for good deliverability.