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Primer · BIMI

BIMI: the brand-logo flex.

9 min read·Updated 2026-04

BIMI (Brand Indicators for Message Identification) is how you get your company logo to appear in the recipient's inbox next to your messages. It requires a certificate (VMC), a correctly-shaped SVG, and — non-negotiable — a DMARC policy stricter than none.

The visible payoff

When BIMI works, recipients in Gmail / Yahoo / Apple Mail / Fastmail see your brand logo in the avatar slot next to your messages instead of a grey monogram circle. It's the single most visible deliverability signal a recipient ever gets — the inbox's way of saying “this sender is verified, you're looking at the real thing.”

Quantified impact varies by brand and audience. Reported lift is usually in the range of 2–10% open-rate uplift for transactional + marketing mail. The larger and more recognisable your logo, the bigger the lift.

The DNS record

BIMI is a TXT record published at default._bimi.<your-domain>:

default._bimi.acme.com.   IN TXT
   "v=BIMI1;
    l=https://acme.com/bimi-logo.svg;
    a=https://acme.com/bimi-cert.pem"

Three tags:

The SVG — why it's never the SVG you have

BIMI requires SVG Tiny 1.2 — specifically the “Portable/Secure” profile. This is a deliberately restrictive subset:

Almost no logo file you have right now meets these constraints. The brand asset shipped from the design team is usually a multi-layered SVG with gradients and effects. Converting to SVG Tiny 1.2 means re-tracing the logo with flat fills, removing every effect, and restructuring the file to BIMI's schema.

For most brands, the right path is to hire someone who's done it before. Mailstinger's Agency tier includes BIMI conversion in the onboarding for tenants on enforced DMARC. We host the SVG at bimi.mailstinger.com/<domain>/logo.svg with the right cache headers.

The VMC — the part that costs money

A Verified Mark Certificate is an X.509 certificate (like an SSL cert, but for trademark verification) issued by a few authorised CAs — DigiCert and Entrust being the dominant ones. To get one you need:

  1. A registered trademark for the logo, with proof of registration (USPTO record, EUIPO, etc.). This rules out smaller brands and unregistered word marks.
  2. The SVG Tiny 1.2 logo file already in compliance.
  3. Validation by the CA — usually 1–3 weeks, similar to EV-cert validation.
  4. Annual fees in the range of $1,300–$2,000 per domain per year. Multiple-domain bundles bring the per-domain cost down somewhat.

The cheaper alternative is a CMC — Common Mark Certificate — which doesn't require a registered trademark and uses common-law rights instead. CMCs work with Yahoo, Apple Mail, and Fastmail. They don't work with Gmail (yet). For most US/EU brands, Gmail represents the inbox where BIMI matters most, so CMC is a partial-coverage answer.

The DMARC prerequisite

BIMI is gated behind DMARC. To display your logo, receivers require:

The reasoning is sound: BIMI is a trust signal. Receivers won't signal trust for a domain whose owner hasn't enforced DMARC. The whole stack is designed so the cheap flex (logo in inbox) is gated by the expensive work (DMARC enforcement). That's by design and it's correct.

Selectors — usually one, sometimes more

The default selector is default, hence default._bimi.acme.com. You can publish multiple selectors for different mail flows by adding an BIMI-Selector header to outgoing mail referencing a non-default selector name. In practice, almost no one uses this; one logo per domain is the rule.

How to know if it's working

Send a test email to a Gmail account, open it, look at the avatar circle. If your logo's there, you're live. If you see a grey monogram, BIMI isn't resolving for one of these reasons (in order of likelihood):

  1. DMARC isn't at quarantine/reject yet.
  2. The SVG fails BIMI validation. Test with the BIMI Group's validator: bimigroup.org/bimi-generator/.
  3. The VMC PEM isn't reachable over HTTPS, or has expired.
  4. Cache — can take 24h after publishing to show.

Our DMARC analyzer checks the DNS-side BIMI record + DMARC policy gating + URL reachability for both the SVG and VMC. If it's all green and Gmail still doesn't render, the fault is almost always in the SVG itself.

Is it worth it?

A clear-eyed take, by brand size:

What's changed recently: Apple Mail BIMI (added 2023) means iPhones now display your logo in the inbox too — previously the carrot was Gmail-only. That tips some mid-sized brands into “yes” territory.

Things people get wrong

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