BIMI Complete Guide: Brand Logos in Email Inboxes

BIMI (Brand Indicators for Message Identification) displays your brand logo directly in email clients next to your messages. It's the visual reward for implementing proper email authentication—and it significantly boosts email engagement.

What is BIMI?

BIMI allows you to publish your brand logo in DNS so that email clients can display it next to authenticated messages. When recipients see your verified logo, they know the email is legitimately from your brand.

How BIMI Works

1. You achieve DMARC enforcement (p=quarantine or p=reject)
2. You create an SVG logo meeting BIMI requirements
3. You optionally obtain a VMC (Verified Mark Certificate)
4. You publish a BIMI DNS record
5. Email clients display your logo

Which Email Clients Support BIMI?

BIMI Requirements

1. DMARC at Enforcement

Required: DMARC policy of p=quarantine or p=reject

v=DMARC1; p=reject; rua=mailto:dmarc@reports.mailsentinel.io

Why: BIMI only works when email is authenticated. DMARC enforcement proves you've implemented proper authentication.

2. SVG Logo File

Your logo must meet specific requirements:

File Format:

• SVG Tiny Portable/Secure (SVG-PS)
• Not standard SVG

Technical Requirements:

• Square aspect ratio
• Centered logo
• No animation
• No external links
• No JavaScript
• Under 32KB file size

Example SVG structure:

<?xml version="1.0" encoding="UTF-8"?>
<svg version="1.2" baseProfile="tiny-ps" xmlns="http://www.w3.org/2000/svg"
     width="512" height="512" viewBox="0 0 512 512">
  <!-- Your logo paths here -->
</svg>

3. Verified Mark Certificate (VMC)

For Gmail and Apple Mail: VMC required

What is a VMC?

• Digital certificate proving you own the trademark
• Issued by authorized Certificate Authorities
• Validates your logo ownership

VMC Providers:

• DigiCert
• Entrust

VMC Cost:

• $1,000-1,500/year

VMC Process:

1. Prove trademark ownership
2. Verify domain control
3. Validate organization
4. Certificate issued
5. Publish in DNS

4. BIMI DNS Record

DNS record format:

Type: TXT
Host: default._bimi
Value: v=BIMI1; l=https://example.com/logo.svg; a=https://example.com/certificate.pem

Components:

• v=BIMI1 - BIMI version
• l= - URL to your SVG logo
• a= - URL to VMC (optional, required for Gmail/Apple)

Setting Up BIMI

Step 1: Achieve DMARC Enforcement

Before BIMI, you must have:

• ✅ SPF configured and passing
• ✅ DKIM configured and passing
• ✅ DMARC at p=quarantine or p=reject
• ✅ High pass rates (95%+)

If you're not at enforcement yet, use MailSentinel to monitor and progress.

Step 2: Create Your Logo

Option A: Convert Existing Logo

Use tools like:

• BIMI Group's SVG converter
• Manual SVG-PS conversion

Option B: Professional Service

Consider professional design services for BIMI-compliant logos.

Logo Best Practices:

• Use your primary brand logo
• Ensure high contrast
• Test at small sizes (32x32px)
• Center the logo in square frame

Step 3: Host Your Logo

Requirements:

• HTTPS URL
• Publicly accessible
• Reliable hosting
• Fast response time

Example:

https://brand.example.com/bimi/logo.svg

Step 4: Obtain VMC (If Required)

For Gmail/Apple Mail support:

1. Register trademark (if not already)
2. Contact VMC provider (DigiCert or Entrust)
3. Complete validation:
   • Trademark verification
   • Domain verification
   • Organization verification
4. Receive certificate
5. Host certificate at HTTPS URL

Step 5: Publish BIMI Record

Without VMC (Yahoo, AOL, Fastmail):

v=BIMI1; l=https://brand.example.com/bimi/logo.svg

With VMC (Gmail, Apple Mail):

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

Step 6: Test Your Implementation

Test Tools:

• BIMI Inspector (bimigroup.org)
• MailSentinel BIMI checker
• MXToolbox BIMI lookup

Verification Checklist:

• DMARC at enforcement
• SVG logo accessible
• SVG meets requirements
• VMC valid (if using)
• BIMI DNS record published
• Test emails show logo

BIMI Without VMC

Supported Email Clients

These clients show BIMI logos without VMC:

• Yahoo Mail
• AOL Mail
• Fastmail

Setup (Without VMC)

1. Achieve DMARC enforcement
2. Create SVG-PS logo
3. Host logo at HTTPS URL
4. Publish BIMI record:

v=BIMI1; l=https://brand.example.com/logo.svg

This is a great starting point while you work toward VMC for Gmail.

ROI of BIMI

Brand Recognition

Studies show:

• 10%+ increase in open rates
• Higher brand recall
• Increased trust
• Better engagement

Spam Differentiation

Your logo visually separates your emails from:

• Spam
• Phishing attempts
• Unknown senders

Investment Analysis

Costs:

• DMARC enforcement: Required anyway
• SVG creation: $200-500 one-time
• VMC: $1,000-1,500/year
• Hosting: Minimal

Returns:

• 10% open rate increase
• Better brand visibility
• Trust signals
• Competitive advantage

Example:

• 1M emails/month
• 20% baseline open rate → 200,000 opens
• 22% with BIMI → 220,000 opens
• 20,000 additional opens/month

Common BIMI Issues

Issue 1: Logo Not Showing

Causes:

• DMARC not at enforcement
• Logo format incorrect
• Logo URL inaccessible
• BIMI record syntax error

Solutions:

• Verify DMARC policy
• Validate SVG format
• Test logo URL accessibility
• Check DNS record

Issue 2: VMC Validation Failing

Causes:

• Trademark not registered
• Domain ownership issues
• Certificate chain problems

Solutions:

• Ensure trademark registration
• Verify domain control
• Contact VMC provider

Issue 3: Logo Displays Incorrectly

Causes:

• Non-square aspect ratio
• Poor contrast
• Complex paths not rendering

Solutions:

• Recreate as square
• Simplify logo
• Test at small sizes

BIMI Best Practices

Logo Design

• ✅ Use recognizable brand mark
• ✅ High contrast colors
• ✅ Clean, simple design
• ✅ Test at 32x32 pixels
• ❌ Don't use text-heavy logos
• ❌ Don't use detailed imagery

Technical Implementation

• ✅ Use CDN for logo hosting
• ✅ Set long cache headers
• ✅ Monitor logo accessibility
• ✅ Test across email clients
• ❌ Don't change logo URL frequently
• ❌ Don't use unreliable hosting

Maintenance

• ✅ Monitor DMARC pass rates
• ✅ Renew VMC annually
• ✅ Update logo if brand changes
• ✅ Test regularly

BIMI Tools

Our Tool

BIMI Lookup Tool

• Check any domain's BIMI status
• Validate logo format
• Verify VMC

Official Resources

• BIMI Group
• BIMI Inspector

Getting Started

Prerequisites

Before implementing BIMI:

1. Set up DMARC monitoring with MailSentinel
2. Achieve DMARC enforcement (p=quarantine or p=reject)
3. Maintain 95%+ pass rates

Implementation Path

Month 1-2: Achieve DMARC enforcement Month 3: Create BIMI logo, publish record (no VMC) Month 4-5: Obtain VMC for Gmail/Apple support Month 6+: Monitor and maintain

Additional Resources

• DMARC Setup Guide - Achieve enforcement
• BIMI Lookup Tool - Check BIMI status
• Email Authentication Checklist - Complete setup guide

Start Your DMARC Journey →