Summary
Transitioning to a new email service provider (ESP) while simultaneously maintaining email sends from your existing platform, all under the same domain, presents a nuanced challenge. The primary concern revolves around managing conflicting DNS records and preserving your sender reputation. It requires a clear understanding of how different email-related domains function, particularly the distinction between the visible From address and the technical envelope From address (also known as the Return-Path or bounce domain).
Key findings
- Domain separation: You must use different subdomains for the envelope From (or Return-Path/Bounce) address for each ESP. This ensures each provider can correctly handle bounces and maintain its own specific authentication records (like SPF and DKIM).
- DNS records: SPF records are specific to subdomains. This means each unique subdomain used for sending will have its own SPF record, preventing conflicts. Similarly, DKIM records should also use distinct selectors for each ESP and subdomain.
- DMARC implications: A DMARC policy of p=reject (or even p=quarantine) requires strict SPF and DKIM alignment. Any misconfiguration during the transition, especially if both ESPs are sending with the same visible From domain, can lead to email rejection or blocking.
- Visible From domain: The visible From address (what recipients see) can remain consistent across both ESPs. DMARC aligns against this domain, ensuring brand consistency while the underlying technical domains (envelope From, DKIM) differ per ESP.
Key considerations
- Gradual warm-up: A gradual warm-up for the new ESP's sending infrastructure (IPs and subdomains) is crucial. This involves slowly increasing sending volume to build a positive reputation with internet service providers (ISPs).
- DNS record accuracy: Precise setup of SPF and DKIM records for each subdomain is essential. Errors can result in authentication failures and impact deliverability. Your new ESP should provide specific DNS records for their service.
- DMARC policy adjustment: Before, during, and after migration, monitor your DMARC reports closely. If your policy is p=reject, consider temporarily moving to p=quarantine or p=none if you encounter significant authentication failures during the overlap period, then return to p=reject once the transition is complete and stable.
- MX record management: While the primary focus is on sending, remember that MX records handle incoming mail (like bounces). If your new ESP handles bounces, the MX record for the bounce domain might need to be updated. Consult your new ESP for their recommendations on this.
- Reputation continuity: Even with different subdomains, the primary domain's reputation affects all associated subdomains. Maintain consistent sending practices (e.g., list hygiene, engagement) across both ESPs to preserve your overall domain reputation.
What email marketers say
Email marketers often face challenges when trying to transition between ESPs while keeping their sending operations active on the old platform. The core concern typically revolves around how to manage DNS records for a single primary domain across two different sending infrastructures without causing deliverability issues or conflicting configurations. Many are unfamiliar with the technical distinctions between various email domains (e.g., visible From vs. envelope From) and the precise requirements for authentication protocols like SPF, DKIM, and DMARC during such a complex migration.
Key opinions
- DNS record complexity: Many marketers find the concept of managing DNS records for multiple ESPs on the same domain confusing, particularly concerning SPF and DKIM. There's often a misconception that a single domain can only have one SPF record that applies universally.
- DMARC policy impact: Marketers recognize that a strict DMARC policy (p=reject) can significantly impact delivery during a transition if not handled carefully, highlighting a general lack of in-depth DMARC knowledge beyond basic setup.
- Gradual transition desire: The preference is to gradually transition to avoid abrupt changes that could affect ongoing campaigns and sender reputation, even if the technical steps seem daunting.
- ESP support reliance: There's an expectation that the new ESP should provide comprehensive support and guidance for the migration process, especially concerning DNS configuration.
Key considerations
- Distinguish domain types: Understand the difference between the visible From domain (user-facing) and the technical envelope From domain (for SPF and bounce handling). This is foundational for a smooth transition with multiple ESPs.
- Plan for warm-up: Even with an existing domain, if the new ESP uses new IPs or subdomains, a structured warm-up process is vital to build reputation and avoid deliverability issues.
- Prioritize authentication: Ensure that SPF, DKIM, and DMARC are correctly configured for all sending subdomains on both ESPs to maintain authentication success and DMARC alignment.
- Leverage ESP expertise: Work closely with your new ESP’s support team, as they can provide precise DNS records and guide you through their specific setup process, especially for complex transitions. Mailjet provides a comprehensive guide on ESP migration tips.
Marketer view
Email marketer from Email Geeks indicates the challenge of gradually transitioning to a new ESP while still sending from the current platform. The primary concern is how to use the same domain for both without conflicting DNS records, which can be a significant hurdle for those less familiar with the technical intricacies of email deliverability.
Marketer view
A marketer from Email Geeks explains that the only potentially conflicting record during an ESP transition is the MX record. They suggest that the timing of switching this record can vary (beginning, middle, or end of migration) and advise relying on the new ESP for guidance on this point.
What the experts say
Email deliverability experts highlight that the perceived complexity of transitioning ESPs with the same primary domain often stems from a misunderstanding of how email authentication (SPF, DKIM, DMARC) interacts with various domain types (e.g., envelope From, visible From). They emphasize the necessity of distinct subdomains for different ESPs' technical sending purposes, even when the end-user sees the same primary brand domain. Proper DNS configuration and careful reputation management are repeatedly stressed as critical for success.
Key opinions
- Separate envelope From: Experts strongly recommend using separate envelope From addresses (and thus separate subdomains) for each ESP to ensure proper bounce handling and independent authentication.
- Subdomain-specific SPF/DKIM: SPF and DKIM records should be configured at the subdomain level for each ESP. This allows multiple ESPs to send on behalf of the same primary domain without conflicting authentication records.
- DMARC alignment critical: For DMARC to pass, either SPF or DKIM must align with the visible From domain. This alignment is paramount, especially under a p=reject policy.
- Domain type confusion: A common source of confusion is the array of domains associated with an email (e.g., visible From, envelope From, DKIM, URL domains). Clarifying these roles is essential for a successful migration.
Key considerations
- Granular DNS control: Ensure your DNS provider allows for the necessary level of granularity to set up multiple SPF and DKIM records for different subdomains under your primary domain.
- Careful DMARC monitoring: Implement DMARC monitoring to gain visibility into authentication results from both ESPs. This allows you to quickly identify and rectify any issues during the transition, especially with a p=reject policy. Learn more about fixing common DMARC issues.
- IP warm-up strategy: Even if the main domain is warmed, the new ESP’s IPs (and any new subdomains) will need a dedicated warm-up. This should be a gradual process to build trust with ISPs. Consider how to warm up a new sending domain.
- Understand domain roles: Familiarize yourself with the various domain roles in email. An expert from Word to the Wise explains the nuances of domains and reputation in detail, which is crucial for complex setups.
Expert view
An expert from Email Geeks clarifies that separate envelope From addresses should be used for each ESP, emphasizing that these subdomains should not be identical. This distinction is crucial for proper bounce handling and ensuring that each ESP's infrastructure is correctly attributed for mail sent through it.
Expert view
An expert from Email Geeks advises using different subdomains for the DKIM 'd=' tag. This practice ensures that DKIM signatures are properly generated and verified by each respective ESP, preventing conflicts and maintaining authentication integrity.
What the documentation says
Official email documentation and standards (such as RFCs) provide the foundational rules for how email authentication mechanisms like SPF, DKIM, and DMARC operate. They underscore that these protocols rely on DNS records associated with specific domains and subdomains. When multiple sending systems (ESPs) are involved for the same primary domain, the documentation implicitly supports the use of distinct subdomains for technical sending, ensuring that each system can independently authenticate mail while maintaining the desired brand identity at the visible From level. This ensures compliance and optimal deliverability.
Key findings
- SPF record placement: RFC 7208 defines SPF as a mechanism where a domain owner specifies authorized sending hosts via a TXT record in the DNS. This record is placed on the specific subdomain used for the envelope From address.
- DKIM signing: RFC 6376 describes DKIM, which uses cryptographic signatures tied to a domain (the 'd=' tag in the DKIM signature). This allows different ESPs to sign mail from distinct subdomains of the same primary domain.
- DMARC aggregation: RFC 7489 states that DMARC unifies SPF and DKIM, requiring at least one to align with the visible From domain for authentication to pass. This is crucial for maintaining a single branding domain while using multiple technical sending sources.
- Reputation consistency: Postmaster guidelines from major ISPs (like Google and Microsoft) stress that maintaining a consistent and positive sender reputation is vital. This includes proper authentication and a gradual warm-up for new sending infrastructure.
Key considerations
- DNS records per subdomain: Documentation implicitly supports creating separate SPF and DKIM records for distinct subdomains (e.g., esp1.yourdomain.com, esp2.yourdomain.com) even if they all point to the same root domain for branding. This is the technical basis for simultaneous sending.
- Careful DMARC policy application: When transitioning and using DMARC with p=reject, ensure that both ESPs are configured correctly to pass SPF and DKIM alignment, as specified by RFC 7489. Failure to do so will result in email rejection according to your policy.
- Gradual IP warm-up: ISP postmaster guidelines emphasize that any new IP addresses or significantly new sending patterns from a fresh ESP will require a gradual warm-up. This builds trust, regardless of whether the primary domain is established.
- Understanding domain roles: A clear understanding of the different domain roles within an email header (e.g., Header From, Envelope From, DKIM signature domain) as detailed in RFCs and technical documentation is essential for configuring multiple ESPs correctly. GitHub offers a checklist for deliverability recommendations when changing ESPs.
Technical article
RFC 7208 defines SPF (Sender Policy Framework) as a crucial mechanism for domain owners to authorize which hosts can send mail from their domain. It explicitly details that this authorization is managed via a TXT record in the DNS, typically applied to the specific subdomain or domain used in the mail From (envelope From) address.
Technical article
RFC 6376, which outlines DKIM (DomainKeys Identified Mail), explains how email senders can cryptographically sign their emails. This signature allows recipients to verify both the sender's authenticity and the integrity of the email content, confirming it has not been tampered with since signing.
Related resources
10 resources
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