Brand Indicators for Message Identification

Brand Indicators for Message Identification, or BIMI (/ˈbɪmi/), is a specification allowing for the display of brand logos next to authenticated e-mails.

Design

There are two parts to BIMI: a method for domain owners to publish the location of their indicators, and a means for mail transfer agents (MTAs) to verify the authenticity of the indicator. To implement BIMI, companies need a valid DMARC DNS record with a policy of either quarantine or reject, an exact square logo for the brand in SVG Tiny P/S format, and a DNS TXT record for the domain indicating the URI location of the SVG file. The only supported transport for the SVG URI is HTTPS. The BIMI DNS record is in the following format:

default._bimi   TXT   "v=BIMI1; l=https://example.com/logo.svg; a=https://example.com/image/certificate.pem"

(The a= part is optional. When present, it defines an evidence document; the only current form of this file is called a Verified Mark Certificate (VMC). When absent, the BIMI record is considered self-asserted.) Additionally, services such as Gmail require that a VMC be acquired and presented with the TXT record in order for the brand logo to be displayed in the inbox. These factors alone will not guarantee a BIMI logo will be displayed as heuristics (like spam and spoofing) and reputation will be a key part in BIMI validity.

To query the value of the default._bimi TXT record for a given domain, one can use the dig command-line tool. For example, the following command will query the TXT record for the example.com domain: 

dig +short default._bimi.example.com TXT

Implementations

A working group of several companies named "BIMI Group" has formed to develop and support standardization of BIMI in IETF. As of June 2023 the following e-mail services have implemented support for BIMI:

Email clients supporting BIMI
ClientRequires VMCNotes
AOL MailUnknown
Apple MailYes
FastmailNo
GmailYes
La PosteNo Domains without VMCs must be submitted and manually verified by La Poste.
Yahoo! MailNo Only for bulk messages from high-reputation domains
HalonYes

History

The BIMI Working Group was founded in 2019 and the first Internet Draft was published in October 2021.

Benefits

BIMI provides several advantages for organizations implementing email authentication:

  1. Increased Trust and Brand Recognition – BIMI displays verified brand logos directly in recipients' inboxes, building trust and visibility before an email is opened.
  2. Higher Engagement and Deliverability – Recognizable brand logos help improve open rates and click-through rates, while BIMI requires a strong DMARC policy that enhances email authentication and deliverability.
  3. Protection Against Phishing and Spoofing – BIMI enforces domain authentication (SPF, DKIM, DMARC) and verified mark certificates (VMC), helping to prevent misuse of brand identity in fraudulent emails.

Contributors

The contributors of BIMI specifications, called the BIMI Group, also called Authindicators Working Group, include:

References

  1. 1 2 "Brand Indicators for Message Identification (BIMI) Draft". Internet Engineering Task Force. IETF Trust. Retrieved 5 May 2023.
  2. ↑ "BIMI Up, Scotty! A look at Brand Indicators for Message Identification (BIMI) Adoption with R and the Alexa Top 1m". Security Boulevard. 2020-02-21. Retrieved 2021-02-08.
  3. ↑ "Implementation Guide". BIMI Group. Archived from the original on 17 March 2026. Retrieved 9 February 2021.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  4. ↑ "Get your Verified Mark Certificate (VMC) - Google Workspace Admin Help". support.google.com. Retrieved 2023-01-25.
  5. ↑ "VMCs Aren't a Golden Ticket for BIMI Logo Display". BIMI Group. 2021-09-10. Archived from the original on 2026-02-16. Retrieved 2023-01-25.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  6. ↑
  7. ↑ "BIMI Support by Mailbox Provider". BIMI Group. Archived from the original on 2026-03-31. Retrieved 2023-06-09.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  8. ↑ "BIMI support in AOL Mail". AOL Help. Retrieved 2023-06-09.
  9. ↑ "Prepare your email server for BIMI support in Apple Mail". Apple Developer. Retrieved 2023-06-09.
  10. ↑ "BIMI Rolling Out to All Apple Inboxes in Fall 2022". BIMI Group. Archived from the original on 2026-02-15. Retrieved 2023-06-09.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  11. ↑ "Using BIMI in Fastmail". Fastmail Help Center. Retrieved 2023-06-09.
  12. ↑ "BIMI for Non-Trademarked Logos". BIMI Group. Archived from the original on 2026-02-28. Retrieved 2023-06-09.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  13. ↑ "Advancing email security for Gmail and beyond with BIMI". Google Workspace Blog. Retrieved 2023-06-09.
  14. ↑ "Add a brand logo to outgoing email with BIMI". Google Workspace Help. Retrieved 2023-06-09.
  15. 1 2 "La Poste Announces Support for BIMI". BIMI Group. Archived from the original on 2026-01-31. Retrieved 2023-06-09.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  16. 1 2 "BIMI, Mail". Yahoo Developer Network. Retrieved 2023-06-09.
  17. 1 2 "Authindicators Working Group | LinkedIn".
  18. ↑ Blank, Seth; Goldstein, Peter; Loder, Thede; Zink, Terry; Bradshaw, Marc; Brotman, Alex (11 October 2021). "Brand Indicators for Message Identification (BIMI)". Internet Engineering Task Force. Retrieved 19 December 2025.
  19. ↑ "BIMI Security Benefits". BIMI Certifications. Retrieved 2025-10-29.
  20. ↑ "Google Joins AuthIndicators Working Group and Commits to BIMI Pilot". BIMI Group. July 24, 2019. Archived from the original on January 12, 2026. Retrieved April 21, 2026.{{cite web}}: CS1 maint: bot: original URL status unknown (link)