BIMI for Developers: Show Your Brand Logo in Every Inbox

What BIMI actually does

Every email client shows a sender avatar next to each message. Without BIMI, that avatar is either a generic initial, a Gravatar, or whatever the client defaults to. With BIMI, your verified brand logo appears instead - consistently, across every message you send.

This matters more for transactional email than marketing. When a user receives a password reset or payment confirmation, seeing your logo instantly signals legitimacy. Without it, security-conscious users may hesitate to click - especially if the email asks them to take action.

Which email clients support BIMI

Prerequisites before you start

BIMI sits at the top of the email authentication pyramid. You cannot implement it without the layers below it already in place and enforced.

1. DMARC at enforcement level

Your domain must have a DMARC policy of p=quarantine or p=reject. A p=none policy (monitoring only) will not work. This is the most common blocker - many teams have DMARC set up but never moved past the monitoring phase.

_dmarc.yourdomain.com  TXT  "v=DMARC1; p=reject; rua=mailto:dmarc@yourdomain.com; pct=100"

2. SPF and DKIM alignment

Both SPF and DKIM must pass and align with your From: domain. If you are using a service like Resend, this means configuring custom DKIM signing and verifying your sending domain - not relying on the shared domain.

3. Verified Mark Certificate (for Gmail)

A VMC is an X.509 certificate that cryptographically ties your logo to your domain. Only two Certificate Authorities issue them: DigiCert and Entrust. The process requires:

• A registered trademark for your logo (with an approved trademark office)
• Organization validation (similar to EV SSL certificates)
• Your logo in SVG Tiny PS format
• Budget: approximately $1,200-$1,500/year

If you do not have a registered trademark, you can still implement BIMI for Apple Mail and Yahoo without a VMC. Gmail added support for Common Mark Certificates (CMCs) as a lower-cost alternative, though adoption is still early.

Implementation: the DNS record

The BIMI record itself is a simple DNS TXT record. It points to your logo file and optionally to your VMC certificate.

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

The l= parameter points to your logo SVG. The a= parameter points to your VMC (omit it if you do not have one). Both URLs must be served over HTTPS.

SVG logo requirements

BIMI logos must follow strict SVG requirements. Regular SVGs from your design team will not work without conversion.

• Format: SVG Tiny 1.2 Portable/Secure (SVG Tiny PS)
• Dimensions: exactly square (1:1 aspect ratio)
• Background: solid color, not transparent
• No external references: no links, no scripts, no embedded images
• File size: under 32KB
• The baseProfile attribute must be set to tiny-ps

<svg version="1.2" baseProfile="tiny-ps"
     xmlns="http://www.w3.org/2000/svg"
     viewBox="0 0 100 100" width="100" height="100">
  <rect width="100" height="100" fill="#1a1a2e" rx="0"/>
  <circle cx="50" cy="50" r="30" fill="#e2b714"/>
  <!-- Your actual logo paths here -->
</svg>

Verifying your BIMI setup

After publishing your DNS record and hosting your SVG, verify the setup before expecting logos to appear.

# Check your BIMI DNS record
dig TXT default._bimi.yourdomain.com

# Verify DMARC is at enforcement level
dig TXT _dmarc.yourdomain.com

# Test your SVG is accessible
curl -I https://yourdomain.com/brand/logo.svg

Online validators to check your full BIMI chain:

• BIMI Group Inspector - validates DNS, SVG, and VMC
• MXToolbox BIMI Lookup - quick DNS check

After validation passes, logo display is not immediate. Gmail caches BIMI lookups and may take 24-48 hours to start showing your logo. Yahoo and Apple Mail are typically faster.

When to implement BIMI (and when to wait)

BIMI and your React Email templates

BIMI operates at the DNS and sending infrastructure level - it does not require any changes to your email templates. Your React Email components continue to work exactly as before. The logo appears in the inbox list view, not inside the email body.

That said, BIMI creates an expectation of brand consistency. If your inbox avatar shows a polished logo but the email inside looks like a plain-text afterthought, the disconnect hurts more than having no logo at all. This is where well-designed templates matter.

import { Html, Head, Body, Container, Img, Text } from "@react-email/components";

// Your BIMI logo appears in the inbox list view.
// Inside the email, use the same brand assets for consistency.
export function PaymentConfirmation({ amount, date }: Props) {
  return (
    <Html>
      <Head />
      <Body style={{ backgroundColor: "#f9fafb", fontFamily: "sans-serif" }}>
        <Container style={{ maxWidth: "560px", margin: "0 auto" }}>
          <Img
            src="https://yourdomain.com/brand/logo-email.png"
            alt="YourBrand"
            width={120}
            height={40}
          />
          <Text style={{ fontSize: "20px", fontWeight: 600 }}>
            Payment of ${amount} confirmed
          </Text>
          <Text>Processed on {date}. No action required.</Text>
        </Container>
      </Body>
    </Html>
  );
}

Real-world impact numbers

The open rate lift is meaningful but secondary. The primary value for SaaS transactional email is the reduction in phishing false positives. When users see your verified logo, they are significantly less likely to ignore or report legitimate auth emails as suspicious.