Suped
How to apply BIMI to a specific subdomain instead of the entire domain?
Summary
To apply BIMI to a specific subdomain, you must create a separate DNS TXT record directly within that subdomain's DNS settings. The record should follow the format `default._bimi.subdomain.example.com` and point to the SVG logo file. Given that BIMI typically trickles down from the apex domain, this subdomain-specific record ensures it only applies to the intended subdomain. Additionally, the subdomain should have a properly enforced DMARC policy (p=quarantine or p=reject), as well as valid SPF, DKIM, and, in some cases, SSL certificates for the logo to display correctly, enabling granular branding control across different subdomains.

Key findings

  • Unique DNS TXT Record: Each subdomain requiring BIMI needs its own dedicated DNS TXT record.
  • Record Format: The DNS TXT record should adhere to the format `default._bimi.subdomain.example.com`.
  • DMARC Enforcement: An enforced DMARC policy (p=quarantine or p=reject) is a key prerequisite.
  • Authentication Mechanisms: Valid SPF and DKIM records are required, and in some cases SSL certificate too.
  • Branding Control: Implementing BIMI at the subdomain level offers greater control over branding for different email streams.

Key considerations

  • DNS Configuration: Ensure meticulous configuration of the DNS TXT record for each subdomain, pointing to the right SVG logo.
  • Authentication Setup: Verify SPF, DKIM, and DMARC are properly configured for the subdomain to ensure BIMI functionality.
  • Record Placement: Make sure the BIMI record resides within the subdomain's DNS settings, not just the main domain.
  • Testing: Thoroughly test BIMI implementation on each subdomain to confirm the logo displays correctly in different email clients.
What email marketers say
7 marketer opinions
To apply BIMI to a specific subdomain instead of the entire domain, you must create a separate, specific DNS TXT record for that subdomain. This record should point to the location of the SVG logo intended for that subdomain. The process mirrors the setup for the main domain but is applied to the subdomain's DNS settings. Additionally, ensuring the subdomain has a properly enforced DMARC policy (p=quarantine or p=reject) and a valid SSL certificate is crucial for BIMI to function correctly. This allows for distinct branding and logo display on different subdomains.

Key opinions

  • Separate DNS Record: A unique DNS TXT record must be created specifically for each subdomain where BIMI is desired.
  • Logo Location: The DNS record must point to the location of the SVG logo file that should be displayed for emails originating from that specific subdomain.
  • DMARC Requirement: An enforced DMARC policy (p=quarantine or p=reject) is essential for BIMI to function correctly on the subdomain.
  • SSL Certificate: A valid SSL certificate is necessary for the subdomain to ensure the logo is displayed correctly.
  • Branding Control: Implementing BIMI on subdomains allows for granular control over branding, enabling different logos for different subdomains.

Key considerations

  • DNS Configuration: Carefully configure the DNS TXT record for each subdomain, ensuring it points to the correct SVG logo location.
  • DMARC Enforcement: Verify that the DMARC policy is properly enforced (p=quarantine or p=reject) for the subdomain.
  • SSL Validation: Ensure that the subdomain has a valid and up-to-date SSL certificate.
  • Testing: Thoroughly test the BIMI implementation on each subdomain to confirm that the logo is displayed correctly in email clients.
Marketer view
Email marketer from dmarcian recommends creating a specific BIMI record for each subdomain you want to enable BIMI on. They emphasize that a properly configured DMARC policy (p=quarantine or p=reject) is a prerequisite for BIMI to function and encourage validation of the subdomain's DNS settings.
14 Jun 2023 - dmarcian
Marketer view
Email marketer from StackOverflow shares that in order to get BIMI working on a subdomain it needs its own DNS record in the subdomain. The record should follow the structure `default._bimi.subdomain.example.com` where the subdomain is included. Ensure you add the URL location of the svg logo.
24 Sep 2024 - StackOverflow
What the experts say
3 expert opinions
Applying BIMI to a specific subdomain requires creating an individual BIMI record directly within the subdomain's DNS settings. This involves setting up a DNS TXT record in the format `default._bimi.subdomain.example.com` and pointing it to the location of your SVG logo. Since BIMI defaults to applying to all subdomains from the apex level, you need to move the record to the subdomain level to restrict it. The subdomain must also have its own DMARC policy, SPF, and DKIM configured for validation.

Key opinions

  • Individual BIMI Records: Each subdomain requires its own individual BIMI record for subdomain-specific application.
  • DNS TXT Record Format: The DNS TXT record should follow the format `default._bimi.subdomain.example.com`.
  • Authentication Requirements: The subdomain must have its own DMARC policy, SPF, and DKIM records configured.
  • Move DNS Record: Move the BIMI DNS record to the subdomain level so it applies only to that subdomain.

Key considerations

  • DNS Configuration: Carefully configure the DNS TXT record for each subdomain, ensuring correct syntax and logo location.
  • Authentication Setup: Ensure proper configuration of DMARC, SPF, and DKIM for the subdomain.
  • Record Placement: Make sure to create the BIMI record within the subdomain's DNS settings, not just the apex domain.
  • BIMI Record Number: Ensure there is only one BIMI record in DNS, for the subdomain.
Expert view
Expert from Email Geeks explains that BIMI trickles down to subdomains from the apex level by default. To apply BIMI only to a subdomain, move the BIMI DNS record to the subdomain level, changing the hostname to include the subdomain (e.g., `default._bimi.test.usnews.com`). He confirms this method should work without breaking the VMC certificate and advises having only one BIMI record in DNS for the subdomain.
8 Dec 2022 - Email Geeks
Expert view
Expert from Spam Resource explains that BIMI on subdomains involves setting up individual BIMI records for each subdomain. You'll need to create a DNS TXT record following the format `default._bimi.subdomain.example.com` pointing to your SVG logo. The subdomain must also have its own DMARC policy, SPF, and DKIM to validate the email.
7 Mar 2023 - Spam Resource
What the documentation says
3 technical articles
Applying BIMI to a specific subdomain involves creating a unique DNS TXT record for that subdomain. This record is created under the '_bimi' subdomain for each specific subdomain (e.g., default._bimi.subdomain.example.com or _bimi.marketing.example.com). This allows you to display different BIMI logos for different subdomains, tailoring visual branding across your email ecosystem. The subdomain must also have valid SPF, DKIM, and DMARC policies in place for BIMI to function correctly.

Key findings

  • Unique DNS TXT Record: A unique DNS TXT record must be created specifically for each subdomain.
  • Record Naming Convention: The DNS TXT record should include the BIMI record name combined with the subdomain (e.g., `default._bimi.subdomain.example.com`).
  • Visual Branding: This allows organizations to tailor their visual branding across different parts of their email ecosystem.
  • Authentication: Valid SPF, DKIM, and DMARC policies are required for the subdomain to function correctly.

Key considerations

  • DNS Configuration: Ensure correct DNS configuration for each subdomain's BIMI record.
  • Authentication Setup: Verify that SPF, DKIM, and DMARC policies are properly configured for each subdomain.
  • Branding Strategy: Plan your visual branding strategy across different subdomains to maintain consistency and relevance.
  • SVG Location: Ensure correct SVG Logo file location is specified in DNS Record.
Technical article
Documentation from Entrust explains that to apply BIMI to a subdomain, create a DNS record specifically for that subdomain. The record name should follow the format `default._bimi.subdomain.example.com`, and the record value should point to the location of your SVG logo file. Ensure that the subdomain also has valid SPF, DKIM, and DMARC policies in place for BIMI to function correctly.
13 Nov 2022 - Entrust
Technical article
Documentation from Agari explains that BIMI supports subdomain implementations by allowing you to define unique BIMI records for each subdomain. This is achieved by creating TXT records under the '_bimi' subdomain for each specific subdomain (e.g., _bimi.marketing.example.com). This enables organizations to tailor their visual branding across different parts of their email ecosystem.
7 Dec 2021 - Agari (Proofpoint)
Start improving your email deliverability today
Get a demo