BIMI Implementation: Building Brand Trust Through Email Authentication

What is BIMI and Why Does It Matter?

BIMI (Brand Indicators for Message Identification) is the visual payoff for your email authentication efforts. When implemented correctly, your verified brand logo appears next to your emails in supported inboxes.

Instead of a generic avatar or initials, recipients see your actual logo—building instant recognition and trust.

**Supported Email Clients:** - Gmail (with VMC certificate) - Yahoo Mail - Apple Mail (iOS 16+, macOS Ventura+) - Fastmail - AOL Mail

Prerequisites: You Must Earn BIMI

BIMI isn't a shortcut—it's a reward for doing email security right. Before you can implement BIMI, you need:

**1. DMARC at Enforcement Level** Your DMARC policy must be at p=quarantine or p=reject with pct=100. No exceptions.

**2. Perfect SPF and DKIM** Both must pass AND align with your From domain.

**3. Good Sender Reputation** Low spam complaints and bounce rates.

**4. Trademark Registration (for Gmail)** Gmail requires a Verified Mark Certificate, which requires a registered trademark.

# Minimum DMARC for BIMI
v=DMARC1; p=quarantine; pct=100; rua=mailto:[email protected]

# Recommended DMARC for BIMI
v=DMARC1; p=reject; rua=mailto:[email protected]; adkim=s; aspf=s

Creating Your BIMI Logo

Your logo must meet strict technical requirements:

**Format:** SVG Tiny 1.2 Portable/Secure (not regular SVG!) **Shape:** Square dimensions **Size:** Maximum 32KB **Background:** Solid color (no transparency for Gmail) **Content:** No scripts, animations, or external references

The logo should be recognizable at small sizes (40x40 pixels) since that's how it appears in many email clients.

The VMC Decision

A Verified Mark Certificate (VMC) is required for Gmail but optional for other providers.

**Get a VMC if:** - Most of your recipients use Gmail - Brand protection is critical for your business - You have a registered trademark

**Skip the VMC (for now) if:** - Your audience primarily uses Yahoo, Apple Mail, or Fastmail - Budget is limited ($1,000-1,500/year) - You're testing BIMI before full investment

VMC providers: DigiCert, Entrust

Implementation Steps

**Step 1:** Create your BIMI-compliant logo

**Step 2:** Host it at a stable HTTPS URL `https://yourdomain.com/bimi/logo.svg`

**Step 3:** (Optional) Obtain VMC certificate

**Step 4:** Add the BIMI DNS record

# Without VMC (works for Yahoo, Apple, Fastmail)
v=BIMI1; l=https://yourdomain.com/bimi/logo.svg

# With VMC (required for Gmail)
v=BIMI1; l=https://yourdomain.com/bimi/logo.svg; a=https://yourdomain.com/bimi/certificate.pem

Measuring BIMI Impact

After implementing BIMI, track these metrics:

- **Open rates:** Many brands see 10-30% increases - **Click rates:** Brand recognition drives engagement - **Phishing reports:** Fewer users report legitimate emails as phishing - **Customer feedback:** Survey recipients about brand recognition

BIMI is more than a logo—it's proof that you take email security seriously.