Brand Indicators for Message Identification (BIMI)

What it is

BIMI lets mailbox providers show your logo next to messages that pass DMARC. It is a visible reward for strong authentication.

Gmail and Apple Mail require a Verified Mark Certificate (VMC) or Common Mark Certificate (CMC) proving you own the logo; Yahoo and some others show self-asserted logos.

How it works

• Your domain must enforce DMARC: p=quarantine (with pct=100) or p=reject, also for subdomains.
• The record is a TXT record at default._bimi.<domain> with v=BIMI1; l= (logo URL) and optionally a= (certificate URL).
• The logo must be SVG Tiny Portable/Secure (SVG Tiny PS): square, no scripts, no external references, served over HTTPS.
• The certificate is a PEM file served over HTTPS containing the VMC/CMC chain.

Example

v=BIMI1; l=https://example.com/bimi/logo.svg; a=https://example.com/bimi/vmc.pem

Common mistakes

• DMARC not enforced

  p=none, or pct below 100, disqualifies the domain from BIMI.

• Regular SVG instead of SVG Tiny PS

  Exported SVGs usually need converting: baseProfile="tiny-ps", version="1.2", a <title>, no x/y attributes on the root.

• Non-square logo

  The logo should be square and centered, since it is often shown in a circle.

• Certificate does not match

  The VMC must cover the domain and embed the same logo you publish.

Specifications

• BIMI Group