DNS and BIMI

What BIMI Does

BIMI — Brand Indicators for Message Identification — lets organizations that have implemented DMARC enforcement display their logo directly in the inbox. When a BIMI-enabled email client (Gmail, Yahoo Mail, and others) receives a message from a BIMI-configured domain, your logo appears next to the sender name.

The practical effect: legitimate emails become visually identifiable at a glance, and phishing attempts that can't pass your DMARC checks cannot display your logo.

Prerequisites

BIMI requires:

1. DMARC policy at p=quarantine or p=reject (p=none is not sufficient)
2. A Verified Mark Certificate (VMC) from an approved certificate authority (DigiCert or Entrust)
3. Your logo in a specific SVG format (SVG Tiny 1.2 profile)
4. A BIMI DNS TXT record

The Verified Mark Certificate

VMCs require trademark registration. The certificate authority verifies that you own the trademark rights to the logo you're displaying. This is what prevents anyone from claiming to display another company's logo.

VMCs typically cost $1,000–$1,500 per year. The trademark verification process adds a few weeks to setup. This is the primary friction point — if your logo isn't trademarked, you'll need to complete that process first.

The BIMI DNS Record

default._bimi.yourdomain.com TXT "v=BIMI1; l=https://yourdomain.com/logo.svg; a=https://yourdomain.com/cert.pem"

The l= points to your hosted SVG logo. The a= points to your VMC.

Client Support

Gmail and Yahoo Mail support BIMI. Microsoft Outlook/365 does not currently implement it. Given that Gmail represents a significant share of business email receipt, BIMI is worthwhile for organizations with strong brand identity and solid email authentication already in place.

Is It Worth It?

For most organizations: only after you have DMARC fully enforced. The DMARC work delivers the real security value — BIMI is the branding benefit that comes after. If you're at p=reject with full email authentication in place and you have a registered trademark on your logo, BIMI is a natural next step. If you haven't completed the DMARC implementation journey, start there.