What is BIMI?

What is BIMI?

BIMI (Brand Indicators for Message Identification) is an email specification that enables organizations to display a verified brand logo next to their emails in the recipient's inbox. It is defined by the AuthIndicators Working Group and works alongside DMARC, DKIM, and SPF to visually identify authenticated senders.

From an end-user perspective, BIMI replaces the generic avatar or initial that most email clients display with your organization's actual logo — provided your domain meets the authentication requirements.

How Does BIMI Work?

When an email arrives, the receiving mail server checks for a BIMI DNS TXT record on the sending domain. If the domain passes DMARC enforcement and the BIMI record points to a valid SVG logo (and optionally a Verified Mark Certificate), the email client displays the logo in the inbox view.

The process follows these steps:

• The sending domain has a DMARC policy of p=quarantine or p=reject.
• The incoming email passes DMARC (SPF or DKIM aligns and passes).
• The receiving server looks up the BIMI DNS record.
• The server fetches the SVG logo from the URL in the record.
• For providers requiring VMC, the certificate is validated.
• The email client renders the logo in the inbox.

Requirements for BIMI

To implement BIMI, your domain must meet the following:

• DMARC enforcement: Your DMARC policy must be set to p=quarantine or p=reject. A policy of p=none does not qualify.
• SVG logo file: Your logo must be in SVG Tiny 1.2 format, hosted on an HTTPS URL. The file must be a square aspect ratio and contain no external references.
• Verified Mark Certificate (VMC): Required by Gmail and some other providers. A VMC is an X.509 certificate issued by an accredited certification authority (currently DigiCert or Entrust) that validates your trademark ownership. VMCs typically cost $1,000–$1,500/year.

BIMI DNS Record Format

The BIMI record is a DNS TXT record published at default._bimi.yourdomain.com:

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

• v=BIMI1 — BIMI version tag (required).
• l= — HTTPS URL to your SVG Tiny 1.2 logo (required).
• a= — HTTPS URL to your VMC PEM file (required for Gmail and Yahoo).

Which Email Providers Support BIMI?

BIMI adoption has grown significantly. Supported providers include:

• Gmail: Supported since 2021 for Google Workspace senders. Requires a VMC. Displays a blue checkmark alongside the logo.
• Yahoo Mail / AOL: Supported since 2020. Requires a VMC as of 2023.
• Apple Mail (iOS 16+ / macOS Ventura+): Displays logos for BIMI-enabled senders. VMC required.
• Fastmail: Supported without VMC requirement.
• Outlook / Microsoft 365: Not yet supported as of early 2026. Microsoft uses its own sender verification system.

Why BIMI Matters

Beyond brand visibility, BIMI provides measurable email security benefits. To qualify, domains must have DMARC enforcement — this means organizations pursuing BIMI are also fully protected against domain spoofing. BIMI effectively creates a market incentive for stricter DMARC adoption.

For marketing and transactional email, showing a verified logo can improve open rates and recipient trust, particularly for brands in regulated industries like finance and healthcare.

Frequently Asked Questions

Do I need a trademark to get BIMI?

To obtain a Verified Mark Certificate (required by Gmail and Yahoo), yes — your logo must be a registered trademark in the relevant jurisdiction. The VMC certification authority will verify trademark ownership as part of the issuance process. Without a VMC, BIMI records without the a= tag may still work with some providers that do not require VMC validation.

What SVG format does BIMI require?

BIMI requires SVG Tiny 1.2 format (also called SVG-P). Standard SVG files exported from tools like Illustrator often contain unsupported features. You must convert or validate your SVG against the SVG Tiny 1.2 profile — several online validators exist for this purpose. The file should ideally be under 32KB.

Can I use BIMI on a subdomain?

Yes. You can publish a BIMI record for a specific subdomain at default._bimi.subdomain.example.com. If no subdomain record exists, email clients will fall back to the organizational domain record. This allows different business units to use different logos.